Network Hyperexcitability in Early Alzheimer’s Disease: Is Functional Connectivity a Potential Biomarker?

Brain Topography, Journal Year: 2023, Volume and Issue: 36(4), P. 595 - 612

Published: May 12, 2023

Network hyperexcitability (NH) is an important feature of the pathophysiology Alzheimer's disease. Functional connectivity (FC) brain networks has been proposed as a potential biomarker for NH. Here we use whole computational model and resting-state MEG recordings to investigate relation between FC. Oscillatory activity was simulated with Stuart Landau on network 78 interconnected regions. FC quantified amplitude envelope correlation (AEC) phase coherence (PC). recorded in 18 subjects subjective cognitive decline (SCD) mild impairment (MCI). determined corrected AECc lag index (PLI), 4-8 Hz 8-13 bands. The excitation/inhibition balance had strong effect both AEC PC. This different PC, influenced by structural coupling strength frequency band. Empirical matrices SCD MCI showed good AEC, but less so For fit best hyperexcitable range. We conclude that sensitive changes E/I balance. more than PLI, results were better thetaband alpha conclusion supported fitting empirical data. Our study justifies functional measures surrogate markers

Language: Английский

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Resting state electroencephalographic alpha rhythms are sensitive to Alzheimer’s disease mild cognitive impairment progression at a 6-month follow-up

Neurobiology of Aging, Journal Year: 2024, Volume and Issue: 137, P. 19 - 37

Published: Feb. 2, 2024

Are posterior resting-state electroencephalographic (rsEEG) alpha rhythms sensitive to the Alzheimer's disease mild cognitive impairment (ADMCI) progression at a 6-month follow-up? Clinical, cerebrospinal, neuroimaging, and rsEEG datasets in 52 ADMCI 60 Healthy old seniors (equivalent groups for demographic features) were available from an international archive (www.pdwaves.eu). The patients arbitrarily divided into two groups: REACTIVE UNREACTIVE, based on reduction (reactivity) eLORETA source activities eyes-closed eyes-open condition ≥ -10% -10%, respectively. 75% of REACTIVE. Compared UNREACTIVE group, group showed (1) less abnormal activity during (2) decrease that follow-up. These effects could not be explained by neuroimaging neuropsychological biomarkers AD. Such biomarker might reflect abnormalities cortical arousal quiet wakefulness used clinical studies using follow-ups.

Language: Английский

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The association between posterior resting-state EEG alpha rhythms and functional MRI connectivity in older adults with subjective memory complaint

Neurobiology of Aging, Journal Year: 2024, Volume and Issue: 137, P. 62 - 77

Published: Feb. 28, 2024

Resting-state eyes-closed electroencephalographic (rsEEG) alpha rhythms are dominant in posterior cortical areas healthy adults and abnormal subjective memory complaint (SMC) persons with Alzheimer's disease amyloidosis. This exploratory study 161 SMC participants tested the relationships between those seed-based resting-state functional magnetic resonance imaging (rs-fMRI) connectivity thalamus visual networks as a function of brain amyloid burden, revealed by positron emission tomography cognitive reserve, measured educational attainment. The were divided into 4 groups according to 2 factors: Education (Edu+ Edu-) Amyloid burden (Amy+ Amy-). There was statistical interaction (p < 0.05) two factors, subgroup analysis using estimated marginal means showed positive association mentioned rs-fMRI rsEEG low amyloidosis high CR (Amy-/Edu+). These results suggest that persons, early may contrast beneficial effects reserve on neurophysiological oscillatory mechanisms at frequencies networks.

Language: Английский

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Network Hyperexcitability in Early-Stage Alzheimer’s Disease: Evaluation of Functional Connectivity Biomarkers in a Computational Disease Model

Journal of Alzheimer s Disease, Journal Year: 2024, Volume and Issue: 99(4), P. 1333 - 1348

Published: May 17, 2024

Background: There is increasing evidence from animal and clinical studies that network hyperexcitability (NH) may be an important pathophysiological process potential target for treatment in early Alzheimer’s disease (AD). Measures of functional connectivity (FC) have been proposed as promising biomarkers NH, but it unknown which measure has the highest sensitivity early-stage changes excitation/inhibition balance. Objective: We aim to test performance different FC measures detecting NH at earliest stage using a computational approach. Methods: use whole brain model activity dependent degeneration simulate progressive AD pathology NH. investigate if what four (amplitude envelope correlation corrected [AECc], phase lag index [PLI], joint permutation entropy [JPE] new measure: time [PLT]) can detect pathophysiology. Results: The replicates spectral line with data demonstrates Compared relative theta power gold standard AECc PLI are shown less sensitive AD-related neurophysiological abnormalities, while JPE PLT show more excellent characteristics. Conclusions: Novel measures, better rapid fluctuations neural connectivity, superior well-known such abnormalities particular AD. These markers could improve diagnosis identification.

Language: Английский

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Parallel electrophysiological abnormalities due to COVID‐19 infection and to Alzheimer's disease and related dementia

Alzheimer s & Dementia, Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 29, 2024

Many coronavirus disease 2019 (COVID-19) positive individuals exhibit abnormal electroencephalographic (EEG) activity reflecting "brain fog" and mild cognitive impairments even months after the acute phase of infection. Resting-state EEG abnormalities include slowing (reduced alpha rhythm; increased slow waves) epileptiform activity. An expert panel conducted a systematic review to present compelling evidence that deficits due COVID-19 Alzheimer's related dementia (ADRD) are driven by overlapping pathologies neurophysiological abnormalities. seen in patients resemble those observed early stages neurodegenerative diseases, particularly ADRD. It is proposed similar Long COVID ADRD parallel neuroinflammation, astrocyte reactivity, hypoxia, neurovascular injury. These underpinning decline can be detected routine exams. Future research will explore value monitoring for predicting long-term outcomes efficacy therapeutic interventions. HIGHLIGHTS: Abnormal intrinsic electrophysiological brain activity, such as EEG, reduced wave, characteristic findings patients. have potential neural biomarkers identify neurological complications at stage disease, assist clinical assessment, assess risk Similar typically with impairments, Evidence presented supports idea resulting, least part, from neuroinflammatory mechanisms reactivity. Identifying common biological highlight critical underlying disorders decline. elucidates questions regarding impairment not yet been adequately investigated.

Language: Английский

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A Real-Time Neurophysiologic Stress Test for the Aging Brain: Novel Perioperative and ICU Applications of EEG in Older Surgical Patients

Neurotherapeutics, Journal Year: 2023, Volume and Issue: 20(4), P. 975 - 1000

Published: July 1, 2023

As of 2022, individuals age 65 and older represent approximately 10% the global population [1], adults make up more than one third anesthesia surgical cases in developed countries [2, 3]. With > 234 million major procedures performed annually worldwide [4], this suggests that 70 surgeries are on across globe each year. The most common postoperative complications seen these patients perioperative neurocognitive disorders including delirium, which associated with an increased risk for mortality [5], greater economic burden [6, 7], developing long-term cognitive decline [8] such as Alzheimer's disease and/or related dementias (ADRD). Thus, anesthesia, surgery, hospitalization have been viewed a biological "stress test" aging brain, delirium indicates failed stress test consequent later (see Fig. 3). Further, it has hypothesized interventions prevent might reduce decline. Recent advances suggest rather waiting development to indicate whether patient "passed" or "failed" test, status brain can be monitored real-time via electroencephalography (EEG) period. Beyond traditional intraoperative use EEG monitoring anesthetic titration, may viable tool identifying waveforms indicative reduced integrity potential In principle, research incorporating routine provide insight into neuronal patterns dysfunction decline, even specific types aging-related neurodegenerative pathology. This would accelerate our understanding necessitate diagnostic workup intervention period, could potentially dementia risk. here we present recommendations "predictor" patients.

Language: Английский

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Abnormal electroencephalographic rhythms from quiet wakefulness to light sleep in Alzheimer’s disease patients with mild cognitive impairment

Clinical Neurophysiology, Journal Year: 2025, Volume and Issue: 171, P. 164 - 181

Published: Jan. 31, 2025

Language: Английский

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Alpha Rhythm and Alzheimer’s Disease: Has Hans Berger’s Dream Come True?

Clinical Neurophysiology, Journal Year: 2025, Volume and Issue: 172, P. 33 - 50

Published: Feb. 14, 2025

Language: Английский

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Human Brain Responses and Functional Brain Networks Across the Lifespan

Brain Sciences, Journal Year: 2025, Volume and Issue: 15(4), P. 402 - 402

Published: April 16, 2025

Measuring brain responses in real time using electrophysiology enriches our understanding of changes behavior and cognitive function across the lifespan [...].

Language: Английский

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Characterizing the heterogeneity of neurodegenerative diseases through EEG normative modeling

npj Parkinson s Disease, Journal Year: 2025, Volume and Issue: 11(1)

Published: May 8, 2025

Abstract Neurodegenerative diseases like Parkinson’s (PD) and Alzheimer’s (AD) exhibit considerable heterogeneity of functional brain features within patients, complicating diagnosis treatment. Here, we use electroencephalography (EEG) normative modeling to investigate neurophysiological mechanisms underpinning this heterogeneity. Resting-state EEG data from 14 clinical units included healthy adults ( n = 499) patients with PD 237) AD 197), aged over 40. Spectral source connectivity analyses provided for modeling, revealing significant, frequency-dependent deviations high in AD. Around 30% exhibited spectral deviations, while ~80% showed deviations. Notably, the spatial overlap deviant did not exceed 60% 25% analysis. Furthermore, patient-specific correlated measures, greater linked worse UPDRS ⍴ 0.24, p 0.025) MMSE −0.26, 0.01). These results suggest that could enrich individualized assessment Precision Neurology.

Language: Английский

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