Journal of dementia and Alzheimer's disease, Journal Year: 2025, Volume and Issue: 2(2), P. 12 - 12
Published: May 2, 2025
Background/Objectives: Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that disrupts functional brain connectivity, leading to cognitive and decline. Electroencephalography (EEG), noninvasive cost-effective technique, has gained attention as promising tool for studying network alterations in AD. This study aims leverage EEG-derived connectivity metrics differentiate between healthy controls (HC), subjective decline (SCD), mild impairment (MCI), AD, offering insights into progression. Methods: Using graph theory-based analysis, we extracted key from resting-state EEG signals, focusing on the betweenness centrality clustering coefficient. Statistical analysis was conducted across multiple frequency bands, discriminant applied evaluate classification performance of metrics. Results: Our findings revealed increase theta-band concurrent decrease alpha- beta-band centrality, reflecting AD-related reorganization. Among examined metrics, exhibited highest discriminative power distinguishing AD stages. Additionally, using comparable advanced deep learning models, highlighting their potential predictive biomarkers. Conclusions: demonstrate strong biomarkers early detection monitoring Their effectiveness capturing underscores value clinical diagnostic workflows, scalable interpretable alternative learning-based models classification.
Language: Английский
Citations
0Personalized brain models link cognitive decline progression to underlying synaptic and connectivity degeneration
Alzheimer s Research & Therapy, Journal Year: 2025, Volume and Issue: 17(1)
Published: April 5, 2025
Cognitive decline is a condition affecting almost one sixth of the elder population and widely regarded as first manifestations Alzheimer's disease. Despite extensive body knowledge on condition, there no clear consensus structural defects neurodegeneration processes determining cognitive evolution. Here, we introduce Brain Network Model (BNM) simulating effects neural activity during processing. The model incorporates two key parameters accounting for distinct pathological mechanisms: synaptic degeneration, primarily leading to hyperexcitation, brain disconnection. Through parameter optimization, successfully replicated individual electroencephalography (EEG) responses recorded task execution from 145 participants spanning different stages decline. cohort included healthy controls, patients with subjective (SCD), those mild impairment (MCI) Alzheimer type. inversion, generated personalized BNMs each participant based EEG recordings. These models revealed network configurations corresponding patient's virtual levels directly proportional severity Strikingly, uncovered neurodegeneration-driven phase transition regimes underlying execution. On either side this transition, increasing degeneration induced changes in that closely mirrored experimental observations across stages. This enabled link hyperexcitation severity. Furthermore, pinpointed posterior cingulum fiber driver transition. Our findings highlight potential account evolution while elucidating neurodegenerative mechanisms. approach provides novel framework understanding how functional alterations contribute deterioration along continuum.
Language: Английский
Citations
0Resting state connectivity biomarkers of seizure freedom after epilepsy surgery
NeuroImage Clinical, Journal Year: 2024, Volume and Issue: 44, P. 103673 - 103673
Published: Jan. 1, 2024
Alterations in brain networks may cause the lowering of seizure threshold and hypersynchronization that underlie recurrence unprovoked seizures epilepsy. The aim this work is to estimate functional network characteristics, which help predicting outcome epilepsy surgery. Twenty patients were studied (11 females, 9 males, mean age 33 years) with scalp-recorded HD-EEG resting state (eyes closed, no interictal discharges) before intracranial evaluation, allowed precise determination epileptogenic zone. Dipole source time courses estimated using Weighted Minimum Norm Estimate based on signals. Information inflow outflow atlas-based regions computed partial directed connectivity. A set graph measures for pairwise connections standard EEG frequency bands was calculated. After surgery 10 seizure-free (Engel 1a) continued suffering from worse than 1a). Inflow containing zone beta delta significantly lower who achieved seizure-freedom after surgery, compared have (p = 0.012, p 0.026, respectively). Average path length band higher freedom 0.012). In band, local efficiency clustering coefficient (0.033, 0.046). preoperative analysis epileptic exhibited stronger separation region onset zone, less information. contrast, shorter paths within facilitate hypersynchronous neuronal activity thus non-seizure free patients. This study supports hypothesis properties might define suitable candidates
Language: Английский
Citations
2Hippocampal hub failure is linked to long-term memory impairment in anti-NMDA-receptor encephalitis: insights from structural connectome graph theoretical network analysis
Journal of Neurology, Journal Year: 2024, Volume and Issue: 271(9), P. 5886 - 5898
Published: July 8, 2024
Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is characterized by distinct structural and functional brain alterations, predominantly affecting the medial temporal lobes hippocampus. Structural connectome analysis with graph-based investigations of network properties allows for an in-depth characterization global local changes their relationship clinical deficits in NMDAR encephalitis.
Language: Английский
Citations
1Functional network disruption in cognitively unimpaired autosomal dominant Alzheimer’s disease: a magnetoencephalography study
Brain Communications, Journal Year: 2024, Volume and Issue: 6(6)
Published: Jan. 1, 2024
Abstract Understanding the nature and onset of neurophysiological changes, selective vulnerability central hub regions in functional network, may aid managing growing impact Alzheimer’s disease on society. However, precise alterations occurring pre-clinical stage human remain controversial. This study aims to provide increased insights quantitative during a true early disease. Using high spatial resolution source-reconstructed magnetoencephalography, we investigated regional whole-brain changes unique cohort 11 cognitively unimpaired individuals with pathogenic mutations presenilin-1 or amyloid precursor protein gene 1:3 matched control group (n = 33) median age 49 years. We examined several magnetoencephalography measures that have been shown robust detecting differences sporadic patients are sensitive excitation-inhibition imbalance. includes spectral power connectivity different frequency bands. also using disruption index. To understand how change as progresses through its stage, correlations between outcomes various clinical variables like were analysed. A comparison mutation carriers controls revealed oscillatory slowing, characterized by widespread higher theta (4–8 Hz) power, lower posterior peak occipital alpha 2 (10–13 power. Functional analyses presented (amplitude-based) (8–13 beta (13–30 bands, predominantly located parieto-temporal regions. Furthermore, found significant index for (phase-based) band, attributed both ‘non-hub’ alongside disruption. Neurophysiological did not correlate indicators progression after multiple comparisons correction. Our findings evidence slowing occur before cognitive impairment autosomal dominant leading The direction these comparable those observed stages disease, suggest an imbalance, fit activity-dependent degeneration hypothesis. These prove useful diagnosis intervention future.
Language: Английский
Citations
1Minimum spanning tree analysis of unimpaired individuals at risk of Alzheimer’s disease
Brain Communications, Journal Year: 2024, Volume and Issue: 6(5)
Published: Jan. 1, 2024
Abstract Identifying early and non-invasive biomarkers to detect individuals in the earliest stages of Alzheimer’s disease continuum is crucial. As a result, electrophysiology plasma are emerging as great candidates this pursuit due their low invasiveness. This first magnetoencephalography study assess relationship between minimum spanning tree parameters, an alternative overcome comparability thresholding problem issues characteristic conventional brain network analyses, phosphorylated tau231 levels unimpaired individuals, with different risk disease. Seventy-six available recordings determination were included. The for theta, alpha beta bands each subject was obtained, leaf fraction, hierarchy diameter calculated. To these topological parameters tau231, we performed correlation whole sample considering two sub-groups separately. Increasing concentrations associated greater fraction values, along lower theta frequency bands. These results emerged higher group, but not group. Our indicate that topology cognitively elevated levels, marker pathology amyloid-β accumulation, already altered, shifting towards more integrated increasing its vulnerability hub-dependency, mostly band. indicated by increases hierarchy, reductions diameter. match initial trajectory proposed theoretical models progression disruption suggest changes function organization begin on.
Language: Английский
Citations
0David Ferrier’s “complex whole”: Early traces of a “brain network” concept
Journal of the History of the Neurosciences, Journal Year: 2024, Volume and Issue: unknown, P. 1 - 11
Published: Sept. 24, 2024
Currently, the idea that brain is a complex network of interacting regions hardly controversial. The rapid development this field often attributed to emergence powerful brain-imaging techniques and, around millennium, merging neuroscience networks with modern mathematical graph theory. However, little known about historical roots concept. It interesting know when first traces concept can be found in work early neuroscientists, how evolved over time, and what factors may have influenced evolution. This study aims set step addressing these questions by detailed analysis David Ferrier's classic study,
Language: Английский
Citations
0Neighbourhood topology unveils pathological hubs in the brain networks of epilepsy-surgery patients
medRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown
Published: Oct. 4, 2024
Abstract Pathological hubs in the brain networks of epilepsy patients are hypothesized to drive seizure generation and propagation. In epilepsy-surgery patients, these have traditionally been associated with resection area: region removed during surgery goal stopping seizures, which is typically used as a proxy for epileptogenic zone. However, recent studies hypothesize that pathological may extend vicinity area, potentially complicating post-surgical control. Here we propose neighbourhood-based analysis organization investigate this hypothesis. We exploit large dataset presurgical MEG (magnetoencephalography)-derived whole-brain from 91 patients. Our neighbourhood-focus two-fold. Firstly, partition regions into three sets, namely resected nodes, their neighbours, remaining network nodes. Secondly, introduce generalized centrality metrics describe neighrbourhood each node, providing regional measure hubness. analyses reveal both area its neighborhood present hub-status, but significant variability across For some, appear area; others, neighborhood. Moreover, does not correlate surgical outcome. These results highlight potential neighborhood-based uncover novel insights connectivity pathologies, need individualized studies, large-enough cohorts, account patient-specific variability.
Language: Английский
Citations
0Connectivity of the neuronal network for contextual fear memory is disrupted in a mouse model of third-trimester binge-like ethanol exposure
bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown
Published: Aug. 19, 2024
Background: In rodents, third-trimester equivalent alcohol exposure (TTAE) produces significant deficits in hippocampal-dependent memory processes such as contextual fear conditioning (CFC). The present study sought to characterize changes both behavior and Fos+ neurons following CFC ethanol (EtOH)-treated versus saline-treated mice using TRAP2:Ai14 that permanently label a tamoxifen injection. We hypothesized TTAE would produce long-lasting disruptions the networks engaged with particular emphasis on limbic system. Methods: On postnatal day 7, received either two injections of saline or 2.5 g/kg EtOH spaced 2 hours apart. were left undisturbed until they reached adulthood, at which point underwent CFC. After context 2, Brain tissue was harvested. Slides automatically imaged Zeiss AxioScanner. Manual counts priori regions interest conducted. Automated performed whole brain QUINT 2D stitching pipeline. Last, novel network analyses applied identify future interest. Results: reduced recall neural density increased CA1 CA3. anteroventral (AV) anterodorsal thalamus. system showed hyperconnectivity male AV shifted affinity towards hippocampal subregions. subparafascicular area basomedial amygdalar nucleus implicated important mediators. Discussion: These results suggest is mediated by disrupted TTAE. Given increase CA3 activity, potential hypothesis causes encoding 1 conditioning. Future studies will aim determine whether this disruption specifically affects retrieval memories.
Language: Английский
Citations
0Connectivity of the neuronal network for contextual fear memory is disrupted in a mouse model of third‐trimester binge‐like ethanol exposure
Alcohol Clinical and Experimental Research, Journal Year: 2024, Volume and Issue: unknown
Published: Dec. 13, 2024
Abstract Background In rodents, third‐trimester‐equivalent alcohol exposure ( TTAE ) produces significant deficits in hippocampal‐dependent memory processes such as contextual fear conditioning CFC ). The present study sought to characterize changes both behavior and Fos + neurons following ethanol EtOH )‐treated versus saline‐treated mice using TRAP2 :Ai14 that permanently label a tamoxifen injection. We hypothesized would produce long‐lasting disruptions the networks engaged with particular emphasis on limbic system. Methods On postnatal day 7, received either two injections of saline or 2.5 g/kg spaced 2 h apart. were left undisturbed until they reached adulthood, at which point underwent . After context 2, Brain tissue was harvested. Slides automatically imaged Zeiss AxioScanner Manual counts priori regions interest conducted. Automated performed whole brain QUINT 2D stitching pipeline. Last, novel network analyses applied identify future interest. Results reduced recall neural density increased CA1 CA3 anteroventral AV anterodorsal thalamus. system showed hyperconnectivity male mice, shifted affinity toward hippocampal subregions. subparafascicular area basomedial amygdalar nucleus implicated important mediators. Discussion These results suggest is mediated by disrupted Given increase activity, potential hypothesis causes encoding 1 conditioning. Future studies will aim determine whether this disruption specifically affects retrieval memories.
Language: Английский
Citations
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