Neuroimaging advances regarding subjective cognitive decline in preclinical Alzheimer’s disease

Molecular Neurodegeneration, Journal Year: 2020, Volume and Issue: 15(1)

Published: Sept. 22, 2020

Subjective cognitive decline (SCD) is regarded as the first clinical manifestation in Alzheimer's disease (AD) continuum. Investigating populations with SCD important for understanding early pathological mechanisms of AD and identifying SCD-related biomarkers, which are critical detection AD. With advent advanced neuroimaging techniques, such positron emission tomography (PET) magnetic resonance imaging (MRI), accumulating evidence has revealed structural functional brain alterations related to symptoms SCD. In this review, we summarize main features key findings regarding AD, from local regional data connectivity-based measures, aim delineating a multimodal signature due Additionally, interaction other risk factors dementia age Apolipoprotein E (ApoE) ɛ4 status, also been described. Finally, possible explanations inconsistent heterogeneous observed individuals discussed, along future directions. Overall, literature reveals preferential vulnerability regions context supporting notion that share similar pattern patients mild impairment (MCI) We conclude these particularly have great potential underlying associated More longitudinal studies larger sample sizes combined more modeling approaches artificial intelligence still warranted establish their utility.

Language: Английский

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The human connectome in Alzheimer disease — relationship to biomarkers and genetics

Nature Reviews Neurology, Journal Year: 2021, Volume and Issue: 17(9), P. 545 - 563

Published: July 20, 2021

Language: Английский

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Cannabis effects on brain structure, function, and cognition: considerations for medical uses of cannabis and its derivatives

The American Journal of Drug and Alcohol Abuse, Journal Year: 2019, Volume and Issue: 45(6), P. 563 - 579

Published: July 31, 2019

Background: Cannabis is the most widely used illicit substance worldwide, and legalization for recreational medical purposes has substantially increased its availability use in United States.Objectives: Decades of research have suggested that cannabis confers risk cognitive impairment across various domains, structural functional differences brain been linked to early heavy use.Methods: With substantial evidence role endocannabinoid system neural development understanding continues into adulthood, rising adolescents young adults raises major concerns. Yet some formulations cannabinoid compounds are FDA-approved uses, including applications children.Results: Potential effects on trajectory morphology cognition, therefore, should be considered. The goal this review update consolidate relevant findings order inform attitudes public policy regarding compounds.Conclusions: point considerations age limits guidelines use.

Language: Английский

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Minor neuropsychological deficits in patients with subjective cognitive decline

Neurology, Journal Year: 2020, Volume and Issue: 95(9)

Published: July 8, 2020

Objective

To determine the nature and extent of minor neuropsychological deficits in patients with subjective cognitive decline (SCD) their association CSF biomarkers Alzheimer disease (AD).

Method

We analyzed data from n = 449 cognitively normal participants (n 209 healthy controls, 240 SCD) an interim release German Center for Neurodegenerative Diseases Longitudinal Cognitive Impairment Dementia Study (DELCODE). An extensive test battery was applied at baseline which we established a latent, 5 domain factor structure comprising learning memory, executive functions, language abilities, working visuospatial functions. compared groups terms global domain-specific performance correlated different markers AD pathology.

Results

observed worse (Cohen d ≈0.25–0.5, adjusted age, sex differences analysis covariance) performance, abilities SCD group to controls. In addition, these domains moderately (r ≈0.3) associated lower β-amyloid_42/40 β-amyloid₄₂/phosphorylated tau181 whole sample specifically subgroup.

Conclusions

Within spectrum clinically unimpaired (i.e., before mild impairment) is function, abilities. The subtle speaks validity potential use early detection underlying preclinical AD.

Language: Английский

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A review of the application of deep learning in the detection of Alzheimer's disease

International Journal of Cognitive Computing in Engineering, Journal Year: 2021, Volume and Issue: 3, P. 1 - 8

Published: Dec. 15, 2021

Alzheimer's disease (AD) is the most common chronic in elderly, with a high incidence rate. In recent years, deep learning has become popular field of medical image and achieved great success. It preferred method analyzing images, it also attracted degree attention AD detection. Compared general machine technology, model more accurate efficient for This paper introduces ad related biomarkers feature extraction methods, reviews application methods detection, analyzes summarizes detection models. The results show that technology shows good performance

Language: Английский

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Fractal dimension of the brain in neurodegenerative disease and dementia: A systematic review

Ageing Research Reviews, Journal Year: 2022, Volume and Issue: 79, P. 101651 - 101651

Published: May 25, 2022

Sensitive and specific antemortem biomarkers of neurodegenerative disease dementia are crucial to the pursuit effective treatments, required both reliably identify track its progression. Atrophy is structural magnetic resonance imaging (MRI) hallmark neurodegeneration. However in most cases it likely indicates a relatively advanced stage less susceptible treatment as some processes begin decades prior clinical onset. Among emerging metrics that characterise brain shape rather than volume, fractal dimension (FD) quantifies complexity. FD has been applied diverse fields science measure subtle changes elaborate structures. We review application thus far MRI dementia. identified studies involving subjects who met criteria for mild cognitive impairment, Alzheimer's Disease, Vascular Dementia, Lewy Body Frontotemporal Amyotrophic Lateral Sclerosis, Parkinson's Huntington's Multiple Systems Atrophy, Spinocerebellar Ataxia Sclerosis. The early literature suggests usually associated with decline brain. includes examples disease-related change occurring independently atrophy, which if substantiated would represent valuable advantage over other metrics. However, be non-specific exhibit complex spatial temporal patterns. A more harmonious methodological approach across larger number well careful attention technical factors image processing measurement will help better elucidate metric's utility.

Language: Английский

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Detecting Early Cognitive Decline in Alzheimer’s Disease with Brain Synaptic Structural and Functional Evaluation

Biomedicines, Journal Year: 2023, Volume and Issue: 11(2), P. 355 - 355

Published: Jan. 26, 2023

Early cognitive decline in patients with Alzheimer's (AD) is associated quantifiable structural and functional connectivity changes the brain. AD dysregulation of Aβ tau metabolism progressively disrupt normal synaptic function, leading to loss synapses, decreased hippocampal density early atrophy. Advances brain imaging techniques living have enabled transition from clinical signs symptoms-based diagnosis biomarkers-based diagnosis, techniques, quantitative EEG, body fluids sampling. The hippocampus has a central role semantic episodic memory processing. This function critically dependent on intrahippocampal connections many cortical regions, including perirhinal entorhinal cortex, parahippocampal association regions temporal parietal lobes, prefrontal cortex. Therefore, reflected altered intrinsic networks (aka large-scale networks), memory, default mode, salience networks. narrative review discusses recent critical issues related detecting AD-associated markers high-risk or neuropsychologically diagnosed subjective impairment mild impairment.

Language: Английский

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Distinct Disruptive Patterns of Default Mode Subnetwork Connectivity Across the Spectrum of Preclinical Alzheimer’s Disease

Frontiers in Aging Neuroscience, Journal Year: 2019, Volume and Issue: 11

Published: Nov. 13, 2019

Background: The early progression continuum of Alzheimer's disease (AD) has been considered to advance through subjective cognitive decline (SCD), non-amnestic mild impairment (naMCI), and amnestic (aMCI). Altered functional connectivity (FC) in the default mode network (DMN) is regarded as a hallmark AD. Furthermore, DMN can be divided into two subnetworks, anterior posterior subnetworks. However, little known about distinct disruptive patterns subsystems across preclinical AD spectrum. This study investigated (aDMN) (pDMN) Methods: Resting-state magnetic resonance imaging (rs-fMRI) was used investigate FC subnetworks 20 healthy controls (HC), eight SCD, 11 naMCI, 28 aMCI patients. Moreover, correlation analysis examine associations between altered neurocognitive performance. Results: Compared HC, SCD patients showed increased bilateral superior frontal gyrus (SFG), naMCI left inferior parietal lobule (IPL), IPL aDMN; while decreased precuneus, middle temporal (MTG), also right (MFG) pDMN. Notably, ventromedial prefrontal cortex (vmPFC) MFG aDMN associated with episodic memory groups. Interestingly, cingulated (PCC) several regions pDMN other functions Conclusions: demonstrates that three stages exhibit alternations patient group data involves function. These findings provide novel insights for tailored clinical intervention

Language: Английский

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Functional neuroimaging in subjective cognitive decline: current status and a research path forward

Alzheimer s Research & Therapy, Journal Year: 2020, Volume and Issue: 12(1)

Published: March 9, 2020

Subjective cognitive decline is a putative precursor to dementia marked by perceived worsening of function without overt performance issues on neuropsychological assessment. Although healthy older adults with subjective may normally, indicate incipient and predict future deterioration. Therefore, the experience represents possible entry point for clinical intervention. However, intervention requires physical manifestation neuroabnormality both corroborate target clinically. While some individuals harbor pathophysiology specific neurodegenerative disorders, many do not display clear indicators. Thus, disorder-agnostic brain measures could be useful track trajectory decline, functional neuroimaging in particular sensitive detect have ability disease-related change when underlying disease etiology remains unclear. this review, we discuss studies reconciliations inconsistent findings. We conclude proposing model where noisy signal propagation inefficient processing across whole-brain networks lead research directions guided model.

Language: Английский

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Repetitive Transcranial Magnetic Stimulation Induced Hypoconnectivity Within the Default Mode Network Yields Cognitive Improvements in Amnestic Mild Cognitive Impairment: A Randomized Controlled Study

Journal of Alzheimer s Disease, Journal Year: 2019, Volume and Issue: 69(4), P. 1137 - 1151

Published: May 20, 2019

Repetitive transcranial magnetic stimulation (rTMS) is thought to be effective in alleviating cognitive symptoms patients with amnestic mild impairment (aMCI), but the mechanisms related network modification are poorly understood. Here we tested rTMS efficacy and explored effect of rTMS-induced changes default mode (DMN) their predictive value for treatment response. Twenty-one subjects clinically diagnosed aMCI were recruited complete a 10-session randomized sham-controlled targeting right dorsolateral prefrontal cortex. Resting-state functional resonance imaging tandem neuropsychological assessments administered before after intervention. Changes connectivity DMN relevant brain regions, as well correlations between baseline clinical rating scales calculated order elucidate mechanism response therapy. Compared sham group, group achieved improvement performance significant within DMN. Group×Time interactions found posterior cingulate gyrus fusiform (F (1,19) = 17.154, p 0.001), also left anterior 3.908, 0.063), showing an deactivation Baseline analysis seeds revealed negative correlation AVLT-Recognition score changes. hypoconnectivity associated improvements aMCI. Further, pre-rTMS activity at rest may predictor favorable

Language: Английский

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