Publications by authors named "Stephane Epelbaum"

Background And Objectives: Primary care is often the first point of contact for patients with cognitive complaints, making initial cognitive screening an essential step to avoid delays in diagnosing Alzheimer's disease (AD) at an early stage. We developed MemScreen, a self-administered smartphone application that assesses overall cognition and verbal memory, and evaluated its ability to detect mild cognitive impairment (MCI) in both general and clinical populations.

Methods: We conducted two validation cohort studies: (1) UK-based Whitehall II cohort study (13th wave, 2018-2022) involving a general population (MCI defined by poor performance on a global cognitive score), and (2) five French memory clinics involving patients without dementia (amnestic MCI defined by the Free and Cued Selective Reminding Test).

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Importance: Depressive symptoms are associated with cognitive decline in older individuals. Uncertainty about underlying mechanisms hampers diagnostic and therapeutic efforts. This large-scale study aimed to elucidate the association between depressive symptoms and amyloid pathology.

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Background: There is a need for a reliable, easy-to-use, widely available, and validated tool for timely cognitive impairment identification. We created a computerized cognitive screening tool (Santé-Cerveau digital tool (SCD-T)) including validated questionnaires and the following neuropsychological tests: 5 Word Test (5-WT) for episodic memory, Trail Making Test (TMT) for executive functions, and a number coding test (NCT) adapted from the Digit Symbol Substitution Test for global intellectual efficiency. This study aimed to evaluate the performance of SCD-T to identify cognitive deficit and to determine its usability.

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The anticipation of progression of Alzheimer's disease (AD) is crucial for evaluations of secondary prevention measures thought to modify the disease trajectory. However, it is difficult to forecast the natural progression of AD, notably because several functions decline at different ages and different rates in different patients. We evaluate here AD Course Map, a statistical model predicting the progression of neuropsychological assessments and imaging biomarkers for a patient from current medical and radiological data at early disease stages.

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: Characterizing self- and informant-reported cognitive complaints, as well as awareness of cognitive decline (ACD), is useful for an early diagnosis of Alzheimer's disease (AD). However, complaints and ACD related to cognitive functions other than memory are poorly studied. Furthermore, it remains unclear which source of information is the most useful to distinguish various groups on the AD spectrum.

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Article Synopsis
  • - Tau proteins are essential for neuron function and are linked to neurodegenerative diseases like Alzheimer's and Frontotemporal dementia, where they accumulate abnormally.
  • - A specific genetic duplication at 17q21.31 was found to affect multiple genes, including MAPT, which encodes Tau, leading to increased MAPT mRNA levels in blood samples from affected individuals.
  • - Researchers created a model using iPSC-induced neurons from patients with the duplication to investigate how it causes different tauopathies and the resulting neurodegenerative mechanisms linked to elevated Tau protein levels.
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Background: Temporary disruption of the blood-brain barrier (BBB) using pulsed ultrasound leads to the clearance of both amyloid and tau from the brain, increased neurogenesis, and mitigation of cognitive decline in pre-clinical models of Alzheimer's disease (AD) while also increasing BBB penetration of therapeutic antibodies. The goal of this pilot clinical trial was to investigate the safety and efficacy of this approach in patients with mild AD using an implantable ultrasound device.

Methods: An implantable, 1-MHz ultrasound device (SonoCloud-1) was implanted under local anesthesia in the skull (extradural) of 10 mild AD patients to target the left supra-marginal gyrus.

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Background: The identification of modifiable risk factors for Alzheimer's disease is paramount for early prevention and the targeting of new interventions. We aimed to assess the associations between health conditions diagnosed in primary care and the risk of incident Alzheimer's disease over time, up to 15 years before a first Alzheimer's disease diagnosis.

Methods: In this agnostic study of French and British health records, data from 20 214 patients with Alzheimer's disease in the UK and 19 458 patients with Alzheimer's disease in France were extracted from The Health Improvement Network database.

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Background: We examined the association between preclinical Alzheimer's disease (AD) and undergoing anesthesia and surgery ("surgery" henceforth) in a cohort of elderly individuals with a subjective cognitive decline (SCD).

Methods: Individuals with SCD (N = 268) were enrolled in a longitudinal follow-up study. Participants underwent comprehensive yearly cognitive evaluation for a period of 4 years.

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Article Synopsis
  • The study investigates the prevalence of amyloid aggregation, a key feature of Alzheimer's disease, in individuals with varying cognitive statuses, including those with normal cognition and who have clinical AD dementia.
  • It analyzes how factors like age, sex, educational background, and the method of detecting amyloid (CSF or PET scans) influence the prevalence estimates.
  • Data were collected from 85 study cohorts between 2013 and 2020, using a systematic approach to categorize amyloid measurements as normal or abnormal.
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  • There is limited evidence regarding the traits of individuals with subjective cognitive decline (SCD) who also have amyloid positivity, which is related to Alzheimer's disease.
  • A study of 1640 participants showed that factors like age, clinical setting, and the presence of the APOE ε4 gene are linked to higher amyloid positivity, whereas education level also plays a role.
  • Specific SCD characteristics such as confirmed complaints and lack of depressive symptoms were associated with amyloid positivity, suggesting these traits can aid in identifying individuals who may have amyloid-related cognitive decline.
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Background: Therapeutic research into Alzheimer's disease (AD) has been dominated by the amyloid cascade hypothesis (ACH) since the 1990s. However, targeting amyloid in AD patients has not yet resulted in highly significant disease-modifying effects. Furthermore, other promising theories of AD etiology exist.

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Article Synopsis
  • The study examines how Alzheimer's disease (AD) affects patient treatment over time by analyzing prescription histories of nearly 35,000 patients from 1996 to 2019.
  • In the years leading up to an AD diagnosis, future patients are prescribed more psychotropic drugs than those with mild cognitive impairment (MCI), indicating early recognition of cognitive decline.
  • After an AD diagnosis, there's a significant shift in prescriptions, with a decrease in all types of drugs—including antidementia medications—reflecting changes in treatment priorities and possibly a simplification of care.
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Identifying a poor degree of awareness of cognitive decline (ACD) could represent an early indicator of Alzheimer's disease (AD). (1) to understand whether there is evidence of poor ACD in the pre-dementia stages of AD; (2) to summarize the main findings obtained investigating ACD in AD; (3) to propose a conceptual framework. We searched Scopus, Pubmed, and the reference lists for studies published up to August 2020.

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Combining multimodal biomarkers could help in the early diagnosis of Alzheimer's disease (AD). We included 304 cognitively normal individuals from the INSIGHT-preAD cohort. Amyloid and neurodegeneration were assessed on F-florbetapir and F-fluorodeoxyglucose PET, respectively.

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Microduplications of the 17q21.31 chromosomal region encompassing the MAPT gene, which encodes the Tau protein, were identified in patients with a progressive disorder initially characterized by severe memory impairment with or without behavioral changes that can clinically mimic Alzheimer disease. The unique neuropathological report showed a primary tauopathy, which could not be unanimously classified in a given known subtype, showing both 4R- and 3R-tau inclusions, mainly within temporal cortical subregions and basal ganglia, without amyloid deposits.

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Introduction: The aim of this study was to evaluate the efficacy of a serious exergame in improving the neuropsychiatric symptoms of patients with neurocognitive disorders.

Methods: X-Torp is a serious exergame combining motor and cognitive activities. Ninety-one subjects (mean age = 81.

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Objective: To determine relative frequencies and linguistic profiles of primary progressive aphasia (PPA) variants associated with (progranulin) mutations and to study their neuroanatomic correlates.

Methods: Patients with PPA carrying mutations (PPA-) were selected among a national prospective research cohort of 1,696 patients with frontotemporal dementia, including 235 patients with PPA. All patients with amyloid-positive CSF biomarkers were excluded.

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Article Synopsis
  • - In 2018, a biological definition of Alzheimer's disease based on biomarkers was proposed for research, leading to debates about its application in clinical practice.
  • - Many cognitively healthy individuals can show biomarkers for Alzheimer's without ever showing symptoms, complicating the reliability of these markers for diagnosis.
  • - The International Working Group suggests that only patients with both positive biomarkers and specific Alzheimer's symptoms should be diagnosed, while biomarker-positive healthy individuals should be seen as at-risk rather than having the disease.
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Network analysis provides a rich framework to model complex phenomena, such as human brain connectivity. It has proven efficient to understand their natural properties and design predictive models. In this paper, we study the variability within groups of networks, i.

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