Background: The use of cerebrospinal (CSF) biomarkers in the diagnosis of Alzheimer's disease (AD) has been gaining interest in clinical practice. Although their usefulness has been demonstrated, their potential value in older patients remains debated.
Objectives: To assess whether knowledge of the results of CSF AD biomarkers was associated with the same gain in diagnostic confidence in older adults > 80 than in younger patients.
The hippocampus's vulnerability to trauma-induced stress can lead to pathophysiological disturbances that precipitate the development of posttraumatic stress disorder (PTSD). The mechanisms of resilience that foster remission and mitigate the adverse effects of stress remain unknown. We analyzed the evolution of hippocampal morphology between 2016/2017 and 2018/2019, as well as the memory control mechanisms crucial for trauma resilience.
View Article and Find Full Text PDFBackground: Subclinical depressive symptoms increase the risk of developing Alzheimer's disease (AD). The neurobiological mechanisms underlying this link may involve stress system dysfunction, notably related to the hippocampus which is particularly sensitive to AD. We aimed to investigate the links between blood stress markers and changes in brain regions involved in the stress response in older adults with or without subclinical depressive symptoms.
View Article and Find Full Text PDFBackground: Accumulation of critically short telomeres (CST) is implicated in decreased tissular regenerative capacity and increased susceptibility to degenerative diseases such as Alzheimer's disease (AD). Telomere shortening has also been associated with age-related brain changes. However, it remains unclear whether CST accumulation is directly associated with AD markers or instead amplifies age-related effects, potentially increasing susceptibility of developing AD in cognitively healthy older adults.
View Article and Find Full Text PDFIntroduction: Individuals suffering from PTSD recount the traumatic event using perceptual, emotional and sensory details. Memorization and recall of individual events are influenced by the individual's social function, i.e.
View Article and Find Full Text PDFMeditation is a mental training approach that can improve mental health and well-being in aging. Yet the underlying mechanisms remain unknown. The Medit-Ageing model stipulates that three mechanisms - attentional, constructive, and deconstructive - upregulate positive psycho-affective factors and downregulate negative ones.
View Article and Find Full Text PDFBackground: Shorter telomeres are associated with increased risk of cognitive decline and age-related diseases. Developing interventions to promote healthy aging by preserving telomere integrity is of paramount importance. Here, we investigated the effect of an 18-month meditation intervention on telomere length (TL) measures in older people without cognitive impairment.
View Article and Find Full Text PDFThe words people use in everyday life tell us about their emotions, their mental state and allow us to understand how people process and interpret an event. Previous research has established a link between the content analysis of narrative texts and the psychopathology of people who have experienced trauma. This study examines whether the development of PTSD following exposure to a previous traumatic event alters the way people express themselves in the context of an anxiety-provoking event, the COVID-19 pandemic.
View Article and Find Full Text PDFBackground: People with neurodegenerative diseases may have difficulty learning new information, owing to their cognitive impairments. Teaching them techniques for learning in social contexts could alleviate this difficulty. The present study will examine the performances of patients with Alzheimer's disease and patients with the semantic variant of primary progressive aphasia on a memory test administered in three social contexts.
View Article and Find Full Text PDFObjective: Poor sleep and high levels of repetitive negative thinking (RNT), including future-directed (ie, worry) and past-directed (ie, brooding) negative thoughts, have been associated with markers of dementia risk. The relationship between RNT and sleep health in older adults is unknown. This study aimed to investigate this association and its specificities including multiple dimensions of objective and subjective sleep.
View Article and Find Full Text PDFPurpose: To assess the likely pathogenic/pathogenic (LP/P) variants rates in Mendelian dementia genes and the moderate-to-strong risk factors rates in patients with Alzheimer disease (AD).
Methods: We included 700 patients in a prospective study and performed exome sequencing. A panel of 28 Mendelian and 6 risk-factor genes was interpreted and returned to patients.
Study Objectives: In aging, reduced delta power (0.5-4 Hz) during N2 and N3 sleep has been associated with gray matter (GM) atrophy and hypometabolism within frontal regions. Some studies have also reported associations between N2 and N3 sleep delta power in specific sub-bands and amyloid pathology.
View Article and Find Full Text PDFSleep, 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.
View Article and Find Full Text PDFBackground And Objectives: Sleep disordered breathing (SDB) has been related to amyloid deposition and an increased dementia risk. However, how SDB relates to medial temporal lobe neurodegeneration and subsequent episodic memory impairment is unclear. Our objective was to investigate the impact of amyloid positivity on the associations between SDB severity, medial temporal lobe subregions, and episodic memory performance in cognitively unimpaired older adults.
View Article and Find Full Text PDFBackground And Objectives: Studies are sparse regarding the association between the informant-reported subjective memory decline (informant report) and Alzheimer disease (AD) biomarkers. This study thus aimed at determining the clinical relevance of the informant report throughout the AD clinical continuum, by assessing its specific relationships with amyloid deposition, cognition, and neurodegeneration.
Methods: Participants from the Imagerie Multimodale de la maladie d'Alzheimer à un stade Précoce (IMAP+) primary cohort and the Alzheimer Disease Neuroimaging Initiative (ADNI) replication cohort were included; all underwent multimodal neuroimaging and neuropsychological assessments.
Objective: Rapid eye movement (REM) sleep is markedly altered in Alzheimer's disease (AD), and its reduction in older populations is associated with AD risk. However, little is known about the underlying brain mechanisms. Our objective was to investigate the relationships between REM sleep integrity and amyloid deposition, gray matter volume, and perfusion in aging.
View Article and Find Full Text PDFSleep plays a crucial role in memory consolidation. Recent data in rodents and young adults revealed that fast spindle band power fluctuates at a 0.02-Hz infraslow scale during non-rapid eye movement (NREM) sleep.
View Article and Find Full Text PDFImportance: No lifestyle-based randomized clinical trial directly targets psychoaffective risk factors of dementia. Meditation practices recently emerged as a promising mental training exercise to foster brain health and reduce dementia risk.
Objective: To investigate the effects of meditation training on brain integrity in older adults.
The medial prefrontal cortex is a key region of mindreading belonging to the mentalizing system, a set of brain areas underlying mental state inference based on reasoning on social concepts. The aim of this study was to characterize the functional connectivity between regions involved in mindreading and to highlight the processes it underpins, focusing on the dorsal and ventral parts of the medial prefrontal cortex. We analyzed resting-state functional magnetic resonance imaging of 56 healthy volunteers, to study the relationship between mindreading abilities and functional connectivity of the medial prefrontal cortex.
View Article and Find Full Text PDFVascular risk factors such as hyperglycemia and platelet hyperactivation play a significant role in type 2 diabetes (T2D), a risk factor for AD. We investigated the relationships between glycemia levels, platelet indices (platelet count; mean platelet volume (MPV)) and AD neuroimaging markers in 105 cognitively unimpaired adults, including 21 amyloid-negative older adults (Aβ-neg controls), and 45 amyloid-positive patients with mild cognitive impairment or dementia (Aβ-pos patients). We assessed between-group differences on the two T2D-related vascular risk factors, then the association between blood parameters and multimodal neuroimaging (structural MRI, F-fluorodeoxyglucose, and F-florbetapir-PET) in cognitively unimpaired adults and Aβ-pos patients using multiple regressions.
View Article and Find Full Text PDFBackground: Depressive and anxiety symptoms are frequent in Alzheimer's disease and associated with increased risk of developing Alzheimer's disease in older adults. We sought to examine their relationships to Alzheimer's disease biomarkers across the preclinical and clinical stages of the disease.
Method: Fifty-six healthy controls, 35 patients with subjective cognitive decline and 56 amyloid-positive cognitively impaired patients on the Alzheimer's continuum completed depression and anxiety questionnaires, neuropsychological tests and neuroimaging assessments.
Front Aging Neurosci
June 2022
Tissue-type plasminogen activator (tPA) is a protease known for its fibrinolytic action but is also involved in physiological and pathophysiological aging processes; including amyloid elimination and synaptic plasticity. The aim of the study was to investigate the role of tPA in cognitive and brain aging. Therefore, we assessed the links between tPA plasma concentration and cognition, structural MRI, FDG-PET and Flobetapir-PET neuroimaging in 155 cognitively unimpaired adults (CUA, aged 20-85 years old) and 32 patients with Alzheimer's disease (ALZ).
View Article and Find Full Text PDFAberrant predictions of future threat lead to maladaptive avoidance in individuals with post-traumatic stress disorder (PTSD). How this disruption in prediction influences the control of memory states orchestrated by the dorsolateral prefrontal cortex is unknown. We combined computational modeling and brain connectivity analyses to reveal how individuals exposed and nonexposed to the 2015 Paris terrorist attacks formed and controlled beliefs about future intrusive re-experiencing implemented in the laboratory during a memory suppression task.
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