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Time-based prospective memory (TBPM) is defined as the ability to remember to perform intended actions at a specific time in the future. TBPM is impaired in aging, and this decline has been associated with white-matter alterations within the superior fronto-occipital fasciculus. In the present study, we used resting-state functional magnetic resonance imaging from 22 healthy young (26 ± 5.2 years) and 23 older (63 ± 6.1 years) participants to investigate how age-related alterations in resting-state functional connectivity are related to TBPM performance, and whether these alterations are associated with the white-matter disruptions we have previously observed with diffusion tensor imaging. Whole-brain analyses revealed lower resting-state functional connectivity in older participants compared with younger ones, which in turn correlated with TBPM performance. These correlations were mainly located in the salience network and the parietal part of the frontoparietal network. Our findings suggest that resting-state functional connectivity alterations contribute to the age-related decline in TBPM.
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Memoria Episódica , Sustancia Blanca , Humanos , Anciano , Imagen de Difusión Tensora , Imagen por Resonancia Magnética , Encéfalo/diagnóstico por imagen , Encéfalo/patología , Sustancia Blanca/patología , Mapeo Encefálico , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/patologíaRESUMEN
Medial temporal lobe (MTL) subregions are differentially affected in Alzheimer's disease (AD), with a specific involvement of the entorhinal cortex (ERC), perirhinal cortex and hippocampal cornu ammonis (CA)1. While amyloid (Aß) and APOEε4 are respectively the first molecular change and the main genetic risk factor in AD, their links with MTL atrophy remain relatively unclear. Our aim was to uncover these effects using baseline data from 130 participants included in the Age-Well study, for whom ultra-high-resolution structural MRI, amyloid-PET and APOEε4 genotype were available. No volume differences were observed between Aß + (n = 24) and Aß- (n = 103), nor between APOE4+ (n = 35) and APOE4- (n = 95) participants. However, our analyses showed that both Aß and APOEε4 status interacted with age on CA1, which is known to be specifically atrophied in early AD. In addition, APOEε4 status moderated the effects of age on other subregions (subiculum, ERC), suggesting a more important contribution of APOEε4 than Aß to MTL atrophy in cognitively unimpaired population. These results are crucial to develop MRI-based biomarkers to detect early AD.
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Enfermedad de Alzheimer , Péptidos beta-Amiloides , Anciano , Humanos , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides/metabolismo , Apolipoproteína E4/genética , Atrofia/patología , Genotipo , Imagen por Resonancia Magnética/métodos , Tomografía de Emisión de Positrones , Proteínas tau/metabolismo , Lóbulo Temporal/metabolismoRESUMEN
OBJECTIVE: The objective of this study was to evaluate novel plasma p-tau231 and p-tau181, as well as Aß40 and Aß42 assays as indicators of tau and Aß pathologies measured with positron emission tomography (PET), and their association with cognitive change, in cognitively unimpaired older adults. METHODS: In a cohort of 244 older adults at risk of Alzheimer's disease (AD) owing to a family history of AD dementia, we measured single molecule array (Simoa)-based plasma tau biomarkers (p-tau231 and p-tau181), Aß40 and Aß42 with immunoprecipitation mass spectrometry, and Simoa neurofilament light (NfL). A subset of 129 participants underwent amyloid-ß (18 F-NAV4694) and tau (18 F-flortaucipir) PET assessments. We investigated plasma biomarker associations with Aß and tau PET at the global and voxel level and tested plasma biomarker combinations for improved detection of Aß-PET positivity. We also investigated associations with 8-year cognitive change. RESULTS: Plasma p-tau biomarkers correlated with flortaucipir binding in medial temporal, parietal, and inferior temporal regions. P-tau231 showed further associations in lateral parietal and occipital cortices. Plasma Aß42/40 explained more variance in global Aß-PET binding than Aß42 alone. P-tau231 also showed strong and widespread associations with cortical Aß-PET binding. Combining Aß42/40 with p-tau231 or p-tau181 allowed for good distinction between Aß-negative and -positive participants (area under the receiver operating characteristic curve [AUC] range = 0.81-0.86). Individuals with low plasma Aß42/40 and high p-tau experienced faster cognitive decline. INTERPRETATION: Plasma p-tau231 showed more robust associations with PET biomarkers than p-tau181 in presymptomatic individuals. The combination of p-tau and Aß42/40 biomarkers detected early AD pathology and cognitive decline. Such markers could be used as prescreening tools to reduce the cost of prevention trials. ANN NEUROL 2022;91:548-560.
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Enfermedad de Alzheimer , Disfunción Cognitiva , Proteínas tau , Anciano , Enfermedad de Alzheimer/diagnóstico , Péptidos beta-Amiloides , Biomarcadores , Cognición , Disfunción Cognitiva/diagnóstico por imagen , Humanos , Tomografía de Emisión de Positrones , Proteínas tau/metabolismoRESUMEN
Time-based prospective memory (TBPM) allows us to remember to perform intended actions at a specific time in the future. TBPM is sensitive to the effects of age, but the neural substrates of this decline are still poorly understood. The aim of the present study was thus to better characterize the brain substrates of the age-related decline in TBPM, focusing on macrostructural gray matter and microstructural white matter integrity. We administered a TBPM task to 22 healthy young (26 ± 5.2 years) and 23 older (63 ± 5.9 years) participants, who also underwent volumetric magnetic resonance imaging and diffusion tensor imaging scans. Neuroimaging analyses revealed lower gray matter volumes in several brain areas in older participants, but these did not correlate with TBPM performance. By contrast, an age-related decline in fractional anisotropy in several white-matter tracts connecting frontal and occipital regions did correlate with TBPM performance, whereas there was no significant correlation in healthy young subjects. According to the literature, these tracts are connected to the anterior prefrontal cortex and the thalamus, 2 structures involved in TBPM. These results confirm the view that a disconnection process occurs in aging and contributes to cognitive decline.
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Envejecimiento/fisiología , Encéfalo/fisiopatología , Cognición/fisiología , Disfunción Cognitiva/metabolismo , Adolescente , Adulto , Anciano , Encéfalo/patología , Disfunción Cognitiva/patología , Imagen de Difusión Tensora/métodos , Femenino , Sustancia Gris/patología , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Sustancia Blanca/patología , Adulto JovenRESUMEN
INTRODUCTION: White matter hyperintensities (WMH) are often described in Alzheimer's disease (AD), but their topography and specific relationships with cognition remain unclear. METHODS: Regional WMH were estimated in 54 cognitively impaired amyloid beta-positive AD (Aßpos-AD), compared to 40 cognitively unimpaired amyloid beta-negative older controls (Aßneg-controls) matched for vascular risk factors. The cross-sectional association between regional WMH volume and cognition was assessed within each group, controlling for cerebral amyloid burden, global cortical atrophy, and hippocampal atrophy. RESULTS: WMH volume was larger in Aßpos-AD compared to Aßneg-controls in all regions, with the greatest changes in the splenium of the corpus callosum (S-CC). In Aßpos-AD patients, larger total and regional WMH volume, especially in the S-CC, was strongly associated with decreased cognition. DISCUSSION: WMH specifically contribute to lower cognition in AD, independently from amyloid deposition and atrophy. This study emphasizes the clinical relevance of WMH in AD, especially posterior WMH, and most notably S-CC WMH.
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Enfermedad de Alzheimer , Sustancia Blanca , Enfermedad de Alzheimer/patología , Péptidos beta-Amiloides , Atrofia/patología , Cognición , Estudios Transversales , Humanos , Imagen por Resonancia Magnética , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patologíaRESUMEN
BACKGROUND: As the population ages, maintaining mental health and well-being of older adults is a public health priority. Beyond objective measures of health, self-perceived quality of life (QoL) is a good indicator of successful aging. In older adults, it has been shown that QoL is related to structural brain changes. However, QoL is a multi-faceted concept and little is known about the specific relationship of each QoL domain to brain structure, nor about the links with other aspects of brain integrity, including white matter microstructure, brain perfusion and amyloid deposition, which are particularly relevant in aging. Therefore, we aimed to better characterize the brain biomarkers associated with each QoL domain using a comprehensive multimodal neuroimaging approach in older adults. METHODS: One hundred and thirty-five cognitively unimpaired older adults (mean age ± SD: 69.4 ± 3.8 y) underwent structural and diffusion magnetic resonance imaging, together with early and late florbetapir positron emission tomography scans. QoL was assessed using the brief version of the World Health Organization's QoL instrument, which allows measuring four distinct domains of QoL: self-perceived physical health, psychological health, social relationships and environment. Multiple regression analyses were carried out to identify the independent global neuroimaging predictor(s) of each QoL domain, and voxel-wise analyses were then conducted with the significant predictor(s) to highlight the brain regions involved. Age, sex, education and the other QoL domains were entered as covariates in these analyses. Finally, forward stepwise multiple regressions were conducted to determine the specific items of the relevant QoL domain(s) that contributed the most to these brain associations. RESULTS: Only physical health QoL was associated with global neuroimaging values, specifically gray matter volume and white matter mean kurtosis, with higher physical health QoL being associated with greater brain integrity. These relationships were still significant after correction for objective physical health and physical activity measures. No association was found with global brain perfusion or global amyloid deposition. Voxel-wise analyses revealed that the relationships with physical health QoL concerned the anterior insula and ventrolateral prefrontal cortex, and the corpus callosum, corona radiata, inferior frontal white matter and cingulum. Self-perceived daily living activities and self-perceived pain and discomfort were the items that contributed the most to these associations with gray matter volume and white matter mean kurtosis, respectively. CONCLUSIONS: Better self-perceived physical health, encompassing daily living activities and pain and discomfort, was the only QoL domain related to brain structural integrity including higher global gray matter volume and global white matter microstructural integrity in cognitively unimpaired older adults. The relationships involved brain structures belonging to the salience network, the pain pathway and the empathy network. While previous studies showed a link between objective measures of physical health, our findings specifically highlight the relevance of monitoring and promoting self-perceived physical health in the older population. Longitudinal studies are needed to assess the direction and causality of the relationships between QoL and brain integrity.
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Envejecimiento/psicología , Encéfalo/diagnóstico por imagen , Imagen de Difusión por Resonancia Magnética/métodos , Vida Independiente/psicología , Imagen Molecular/métodos , Calidad de Vida/psicología , Anciano , Anciano de 80 o más Años , Envejecimiento/fisiología , Encéfalo/fisiología , Femenino , Humanos , MasculinoRESUMEN
INTRODUCTION: Older adults experiencing subjective cognitive decline (SCD) have a heightened risk of developing dementia and frequently experience subclinical anxiety, which is itself associated with dementia risk. OBJECTIVE: To understand whether subclinical anxiety symptoms in SCD can be reduced through behavioral interventions. METHODS: SCD-Well is a randomized controlled trial designed to determine whether an 8-week mindfulness-based intervention (caring mindfulness-based approach for seniors; CMBAS) is superior to a structurally matched health self-management program (HSMP) in reducing subclinical anxiety. Participants were recruited from memory clinics at 4 European sites. The primary outcome was change in anxiety symptoms (trait subscale of the State-Trait Anxiety Inventory; trait-STAI) from pre- to postintervention. Secondary outcomes included a change in state anxiety and depression symptoms postintervention and 6 months postrandomization (follow-up). RESULTS: One hundred forty-seven participants (mean [SD] age: 72.7 [6.9] years; 64.6% women; CMBAS, n = 73; HSMP, n = 74) were included in the intention-to-treat analysis. There was no difference in trait-STAI between groups postintervention (adjusted change difference: -1.25 points; 95% CI -4.76 to 2.25) or at follow-up (adjusted change difference: -0.43 points; 95% CI -2.92 to 2.07). Trait-STAI decreased postintervention in both groups (CMBAS: -3.43 points; 95% CI -5.27 to -1.59; HSMP: -2.29 points; 95% CI -4.14 to -0.44) and reductions were maintained at follow-up. No between-group differences were observed for change in state anxiety or depression symptoms. CONCLUSIONS: A time-limited mindfulness intervention is not superior to health self-management in reducing subclinical anxiety symptoms in SCD. The sustained reduction observed across both groups suggests that subclinical anxiety symptoms in SCD are modifiable. ClinicalTrials.gov identifier: NCT03005652.
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Disfunción Cognitiva , Atención Plena , Automanejo , Anciano , Ansiedad/terapia , Trastornos de Ansiedad , Disfunción Cognitiva/terapia , Femenino , Humanos , MasculinoRESUMEN
Age being the main risk factor for Alzheimer's disease, it is particularly challenging to disentangle structural changes related to normal brain ageing from those specific to Alzheimer's disease. Most studies aiming to make this distinction focused on older adults only and on a priori anatomical regions. Drawing on a large, multi-cohort dataset ranging from young adults (n = 468; age range 18-35 years), to older adults with intact cognition (n = 431; age range 55-90 years) and with Alzheimer's disease (n = 50 with late mild cognitive impairment and 71 with Alzheimer's dementia, age range 56-88 years), we investigated grey matter organization and volume differences in ageing and Alzheimer's disease. Using independent component analysis on all participants' structural MRI, we first derived morphometric networks and extracted grey matter volume in each network. We also derived a measure of whole-brain grey matter pattern organization by correlating grey matter volume in all networks across all participants from the same cohort. We used logistic regressions and receiver operating characteristic analyses to evaluate how well grey matter volume in each network and whole-brain pattern could discriminate between ageing and Alzheimer's disease. Because increased heterogeneity is often reported as one of the main features characterizing brain ageing, we also evaluated interindividual heterogeneity within morphometric networks and across the whole-brain organization in ageing and Alzheimer's disease. Finally, to investigate the clinical validity of the different grey matter features, we evaluated whether grey matter volume or whole-brain pattern was related to clinical progression in cognitively normal older adults. Ageing and Alzheimer's disease contributed additive effects on grey matter volume in nearly all networks, except frontal lobe networks, where differences in grey matter were more specific to ageing. While no networks specifically discriminated Alzheimer's disease from ageing, heterogeneity in grey matter volumes across morphometric networks and in the whole-brain grey matter pattern characterized individuals with cognitive impairments. Preservation of the whole-brain grey matter pattern was also related to lower risk of developing cognitive impairment, more so than grey matter volume. These results suggest both ageing and Alzheimer's disease involve widespread atrophy, but that the clinical expression of Alzheimer's disease is uniquely associated with disruption of morphometric organization.
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Envejecimiento , Enfermedad de Alzheimer/patología , Encéfalo/patología , Disfunción Cognitiva/patología , Demencia/patología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Trastornos del Conocimiento/etiología , Trastornos del Conocimiento/patología , Disfunción Cognitiva/metabolismo , Demencia/complicaciones , Progresión de la Enfermedad , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
INTRODUCTION: The Cognitive Debt hypothesis proposes that repetitive negative thinking (RNT), a modifiable process common to many psychological risk factors for Alzheimer's disease (AD) may itself increase risk. We sought to empirically examine relationships between RNT and markers of AD, compared with anxiety and depression symptoms. METHODS: Two hundred and ninety-two older adults with longitudinal cognitive assessments, including 113 with amyloid-positron emission tomography (PET) and tau-PET scans, from the PREVENT-AD cohort and 68 adults with amyloid-PET scans from the IMAP+ cohort were included. All participants completed RNT, anxiety, and depression questionnaires. RESULTS: RNT was associated with decline in global cognition (P = .02); immediate (P = .03) and delayed memory (P = .04); and global amyloid (PREVENT-AD: P = .01; IMAP+: P = .03) and entorhinal tau (P = .02) deposition. Relationships remained after adjusting for potential confounders. DISCUSSION: RNT was associated with decline in cognitive domains affected early in AD and with neuroimaging AD biomarkers. Future research could investigate whether modifying RNT reduces AD risk.
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Enfermedad de Alzheimer/psicología , Péptidos beta-Amiloides/metabolismo , Cognición/fisiología , Disfunción Cognitiva/psicología , Pesimismo/psicología , Lóbulo Temporal/metabolismo , Proteínas tau/metabolismo , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/metabolismo , Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/metabolismo , Femenino , Humanos , Memoria a Corto Plazo/fisiología , Persona de Mediana Edad , Pruebas Neuropsicológicas , Tomografía de Emisión de Positrones , Factores de Riesgo , Lóbulo Temporal/diagnóstico por imagenRESUMEN
Hippocampal connectivity has been widely described but connectivity specificities of hippocampal subfields and their changes in early AD are poorly known. The aim of this study was to highlight hippocampal subfield networks in healthy elderly (HE) and their changes in amnestic patients with mild cognitive impairment (aMCI). Thirty-six HE and 27 aMCI patients underwent resting-state functional MRI scans. Specific intrinsic connectivity of bilateral CA1, SUB (subiculum), and CA2/3/4/DG was identified in HE (using seeds derived from manually delineation on high-resolution scans) and compared between HE and aMCI. Compared to the other subfields, CA1 was more strongly connected to the amygdala and occipital regions, CA2/3/4/DG to the left anterior cingulate cortex, temporal, and occipital regions, and SUB to the angular, precuneus, putamen, posterior cingulate, and frontal regions. aMCI patients showed reduced connectivity within the SUB network (with frontal and posterior cingulate regions). Our study highlighted for the first time three specific and distinct hippocampal subfield functional networks in HE, and their alterations in aMCI. These findings are important to understand AD specificities in both cognitive deficits and lesion topography, given the role of functional connectivity in these processes. Hum Brain Mapp 38:4922-4932, 2017. © 2017 Wiley Periodicals, Inc.
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Disfunción Cognitiva/diagnóstico por imagen , Disfunción Cognitiva/fisiopatología , Hipocampo/diagnóstico por imagen , Hipocampo/fisiopatología , Anciano , Envejecimiento/patología , Envejecimiento/fisiología , Amiloide/metabolismo , Atrofia , Mapeo Encefálico , Disfunción Cognitiva/patología , Simulación por Computador , Femenino , Hipocampo/patología , Humanos , Imagen por Resonancia Magnética , Masculino , Escala del Estado Mental , Método de Montecarlo , Vías Nerviosas/diagnóstico por imagen , Vías Nerviosas/patología , Vías Nerviosas/fisiopatologíaRESUMEN
Prospective memory (PM) refers to the ability to remember to do something in the future, either in response to an event (event-based) or after a certain amount of time has elapsed (time-based). While the distinction between event- and time-based PM is widely acknowledged in the literature, little is known about the processes they share and those they do not. This is particularly true concerning their brain substrates, as almost all neuroimaging studies so far have focused on event-based PM. We proposed a functional magnetic resonance imaging paradigm assessing both event-based and time-based PM to 20 healthy young individuals. Analyses revealed that event- and time-based PM both induced activation in the posterior frontal and parietal cortices, and deactivation in the medial rostral prefrontal cortex. In addition, activation more specific to each condition, which may underlie differences in strategic monitoring, was highlighted. Thus, occipital areas were more activated during event-based PM, probably reflecting target-checking, while a network comprising the dorsolateral prefrontal cortex, the cuneus/precuneus and, to a lesser extent, the inferior parietal lobule, superior temporal gyrus, and the cerebellum, was more activated in time-based PM, which may reflect the involvement of time-estimation processes. These results confirm the allocation of attentional resources to the maintenance of intention for event-based and time-based PM, as well as the engagement of distinct mechanisms reflecting the monitoring strategies specific to each condition.
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Atención/fisiología , Encéfalo/irrigación sanguínea , Encéfalo/fisiología , Intención , Memoria Episódica , Tiempo de Reacción/fisiología , Adolescente , Adulto , Análisis de Varianza , Mapeo Encefálico , Toma de Decisiones Asistida por Computador , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Pruebas Neuropsicológicas , Oxígeno/sangre , Adulto JovenRESUMEN
The ε4 allele of the apolipoprotein E (APOE4) is associated with an increased risk of developing Alzheimer's disease (AD). Hence, several studies have compared the brain characteristics of APOE4 carriers versus non-carriers in presymptomatic stages to determine early AD biomarkers. The present review provides an overview on APOE4-related brain changes in cognitively normal individuals, focusing on the main neuroimaging biomarkers for AD, i.e. cortical beta-amyloid (Aß) deposition, hypometabolism and atrophy. The most consistent findings are observed with Aß deposition as most studies report significantly higher cortical Aß load in APOE4 carriers compared with non-carriers. Fluorodeoxyglucose-positron emission tomography studies are rare and tend to show hypometabolism in brain regions typically impaired in AD. Structural magnetic resonance imaging findings are the most numerous and also the most discrepant, showing atrophy in AD-sensitive regions in some studies but contradicting results as well. Altogether, this suggests a graded effect of APOE4, with a predominant effect on Aß over brain structure and metabolism. Multimodal studies confirm this view and also suggest that APOE4 effects on brain structure and function are mediated by both Aß-dependent and Aß-independent pathological processes. Neuroimaging studies on asymptomatic APOE4 carriers offer relevant information to the understanding of early pathological mechanisms of the disease, although caution is needed as to whether APOE4 effects reflect AD pathological processes, and are representative of these effects in non-carriers.
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Enfermedad de Alzheimer/genética , Péptidos beta-Amiloides/metabolismo , Apolipoproteína E4/genética , Encéfalo/metabolismo , Factores de Edad , Atrofia , Biomarcadores , Encéfalo/patología , Cognición/fisiología , Predisposición Genética a la Enfermedad , Sustancia Gris/metabolismo , Humanos , Factores de RiesgoAsunto(s)
Amiloidosis , Disfunción Cognitiva , Adulto , Envejecimiento , Amiloide , Cognición , HumanosRESUMEN
INTRODUCTION: Older adults experiencing subjective cognitive decline (SCD) have a higher risk of dementia. Reducing this risk through behavioral interventions, which can increase emotional well-being (mindfulness and compassion) and physical activity, is crucial in SCD. METHODS: SCD-Well is a multicenter, observer-blind, randomized, controlled, superiority trial. Three hundred forty-seven participants (mean [standard deviation] age: 72.7 [6.9] years; 64.6% women) were recruited from memory clinics in four European sites to assess the impact of an 8-week caring mindfulness-based approach for seniors (CMBAS) and a health self-management program (HSMP) on mindfulness, self-compassion, and physical activity. RESULTS: CMBAS showed a significant within-group increase in self-compassion from baseline to post-intervention and both a within- and between-group increase to follow-up visit (24 weeks). HSMP showed a significant within- and between-group increase in physical activity from baseline to post-intervention and to follow-up visit. DISCUSSION: Non-pharmacological interventions can differentially promote modifiable factors linked to healthy aging in older adults with SCD.
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Aging is associated with cognitive changes, even in the absence of brain pathology. This study aimed to determine if meditation training, by comparison to active and passive control groups, is linked to changes in the perception of cognitive functioning in older adults. One hundred thirty-four healthy older participants from the Age-Well Randomized Clinical Trial were included: 45 followed a meditation training, 45 a non-native language training and 44 had no intervention. Subjective cognition was assessed at baseline and following the 18-month intervention period. Perception of attentional efficiency was assessed using internal and external Attentional Style Questionnaire (ASQ) subscale scores. Perception of global cognitive capacities was measured via the total score of Cognitive Difficulties Scale (CDS). Deltas ([posttest minus pretest scores]/standard deviation at pretest) were calculated for the analyses. Generalized mixed effects models controlling for age, sex, education and baseline scores revealed that meditation training decreased the vulnerability score toward external distractors measured by the ASQ compared to non-native language training. However, no between-groups differences on ASQ internal or CDS total scores were observed. Results suggest a beneficial effect of meditation practice on perceived management of external distracting information in daily life. Meditation training may cultivate the ability to focus on specific information (e.g., breath) and ignore stimulation from other kinds of stimuli (e.g., noise).
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Introduction: Mental health conditions are associated with cognition and physical function in older adults. We examined whether worry and ruminative brooding, key symptoms of certain mental health conditions, are related to subjective and/or objective measures of cognitive and physical (cardiovascular) health. Methods: We used baseline data from 282 participants from the SCD-Well and Age-Well trials (178 female; agemean = 71.1 years). We measured worry and ruminative brooding using the Penn State Worry Questionnaire and the Ruminative Response Scale-brooding subscale. We assessed subjective physical health using the WHOQOL-Bref physical subscale, and objective physical health via blood pressure and modified versions of the Framingham Risk Score and Charlson Comorbidity Index. With subjective and objective cognition, we utilized the Cognitive Difficulties Scale and a global composite (modified Preclinical Alzheimer's Cognitive Composite, PACC5, with the Wechsler Adult Intelligence Scale-IV, category fluency, Mattis Dementia Rating Scale-2, and either the California Verbal Learning Test or the Rey Auditory Verbal Learning Test). We conducted linear regressions, adjusted for education, age, sex and cohort. Results: Worry and ruminative brooding were negatively associated with subjective physical health (worry: ß = -0.245, 95%CI -0.357 to -0.133, p < 0.001; ruminative brooding: ß = -0.224, 95%CI -0.334 to -0.113, p < 0.001) and subjective cognitive difficulties (worry: ß = 0.196, 95%CI 0.091 to 0.302, p < 0.001; ruminative brooding: ß = 0.239, 95%CI 0.133 to 0.346, p < 0.001). We did not observe associations between worry or ruminative brooding and any measure of objective health. Discussion: Worry and ruminative brooding may be common mechanisms associated with subjective but not objective health. Alternatively, cognitively unimpaired older adults may become aware of subtle changes not captured by objective measures used in this study. Interventions reducing worry and ruminative brooding may promote subjective physical and cognitive health; however, more research is needed to determine causality of the relationships.
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OBJECTIVES: As the world population is ageing, it is vital to understand how older adults can maintain and deepen their psychological well-being as they are confronted with the unique challenges of ageing in a complex world. Theoretical work has highlighted the promising role of intentional mental training such as meditation practice for enhancing human flourishing. However, meditation-based randomised controlled trials in older adults are lacking. We aimed to investigate the effects of meditation training on psychological well-being in older adults. METHODS: This study presents a secondary analysis of the Age-Well trial (ClinicalTrials.gov: NCT02977819), which randomised 137 healthy older adults (age range: 65 to 84 years) to an 18-month meditation training, an active comparator (English language training), or a passive control. Well-being was measured at baseline, mid-intervention, and 18-month post-randomisation using the Psychological Well-being Scale (PWBS), the World Health Organisation's Quality of Life (QoL) Assessment psychological subscale, and composite scores reflecting the meditation-based well-being dimensions of awareness, connection, insight, and a global score comprising the average of these meditation-based dimensions. RESULTS: The 18-month meditation training was superior to English training on changes in the global score (0.54 [95% CI: 0.26, 0.82], p = 0.0002) and the subscales of awareness, connection, insight, and superior to no-intervention only on changes in the global score (0.54 [95% CI: 0.26, 0.82], p = 0.0002) and awareness. Between-group differences in psychological QoL in favour of meditation did not remain significant after adjusting for multiple comparisons. There were no between-group differences in PWBS total score. Within the meditation group, psychological QoL, awareness, insight, and the global score increased significantly from baseline to 18-month post-randomisation. CONCLUSION: The longest randomised meditation training conducted to date enhanced a global composite score reflecting the meditation-based well-being dimensions of awareness, connection, and insight in older adults. Future research is needed to delineate the cognitive, affective, and behavioural factors that predict responsiveness to meditation and thus help refine the development of tailored meditation training.
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Meditación , Humanos , Anciano , Anciano de 80 o más Años , Meditación/métodos , Calidad de Vida , Bienestar Psicológico , Envejecimiento , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
Epidemiological studies show that modifiable risk factors account for approximately 40% of the population variability in risk of developing dementia, including sporadic Alzheimer's disease (AD). Recent findings suggest that these factors may also modify disease trajectories of people with autosomal-dominant AD. With positron emission tomography imaging, it is now possible to study the disease many years before its clinical onset. Such studies can provide key knowledge regarding pathways for either the prevention of pathology or the postponement of its clinical expression. The former "resistance pathway" suggests that modifiable risk factors could affect amyloid and tau burden decades before the appearance of cognitive impairment. Alternatively, the resilience pathway suggests that modifiable risk factors may mitigate the symptomatic expression of AD pathology on cognition. These pathways are not mutually exclusive and may appear at different disease stages. Here, in a narrative review, we present neuroimaging evidence that supports both pathways in sporadic AD and autosomal-dominant AD. We then propose mechanisms for their protective effect. Among possible mechanisms, we examine neural and vascular mechanisms for the resistance pathway. We also describe brain maintenance and functional compensation as bases for the resilience pathway. Improved mechanistic understanding of both pathways may suggest new interventions.
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Sleep, especially slow wave sleep (SWS), is essential for cognitive functioning and is reduced in aging. The impact of sleep quality on cognition is variable, especially in aging. Cognitive reserve (CR) may be an important modulator of these effects. We aimed at investigating this question to better identify individuals in whom sleep disturbances might have greater behavioral consequences. Polysomnography and neuropsychological assessments were performed in 135 cognitively intact older adults (mean age ± SD: 69.4 ± 3.8y) from the Age-Well randomized controlled trial (baseline data). Two measures of cognitive engagement throughout life were used as CR proxies. Linear regression analyses were performed between the proportion of SWS, and executive function and episodic memory composite scores. Then, interaction analyses between SWS and CR proxies on cognition were conducted to assess the possible impact of CR on these links. SWS was positively associated with episodic memory, but not with executive function. CR proxies modulated the associations between SWS and both executive and episodic memory performance. Specifically, individuals with higher CR were able to maintain cognitive performance despite low amounts of SWS. This study provides the first evidence that CR may protect against the deleterious effects of age-related sleep changes on cognition.
Asunto(s)
Reserva Cognitiva , Sueño de Onda Lenta , Anciano , Humanos , Cognición , Vida Independiente , Pruebas Neuropsicológicas , SueñoRESUMEN
OBJECTIVES: Older adults with subjective cognitive decline (SCD) recruited from memory clinics have an increased risk of developing dementia and regularly experience reduced psychological well-being related to memory concerns and fear of dementia. Research on improving well-being in SCD is limited and lacks non-pharmacological approaches. We investigated whether mindfulness-based and health education interventions can enhance well-being in SCD. METHODS: The SCD-Well trial (ClinicalTrials.gov: NCT03005652) randomised 147 older adults with SCD to an 8-week caring mindfulness-based approach for seniors (CMBAS) or an active comparator (health self-management programme [HSMP]). Well-being was assessed at baseline, post-intervention, and 6-month post-randomisation using the Psychological Well-being Scale (PWBS), the World Health Organisation's Quality of Life (QoL) Assessment psychological subscale, and composites capturing meditation-based well-being dimensions of awareness, connection, and insight. Mixed effects models were used to assess between- and within-group differences in change. RESULTS: CMBAS was superior to HSMP on changes in connection at post-intervention. Within both groups, PWBS total scores, psychological QoL, and composite scores did not increase. Exploratory analyses indicated increases in PWBS autonomy at post-intervention in both groups. CONCLUSION: Two non-pharmacological interventions were associated with only limited effects on psychological well-being in SCD. Longer intervention studies with waitlist/retest control groups are needed to assess if our findings reflect intervention brevity and/or minimal base rate changes in well-being.