Directionality of EEG synchronization in Alzheimer's disease subjects

Babiloni, Claudio; Ferri, Raffaele; Binetti, Giuliano; Vecchio, Fabrizio; Frisoni, Giovanni B.; Lanuzza, Bartolo; Miniussi, Carlo; Nobili, Flavio; Rodriguez, Guido; Rundo, Francesco; Cassarino, Andrea; Infarinato, Francesco; Cassetta, Emanuele; Salinari, S.; Eusebi, Fabrizio; Rossini, Paolo Maria

doi:10.1016/j.neurobiolaging.2007.05.007

Cited by 127 publications

(100 citation statements)

References 77 publications

(115 reference statements)

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“…VS were characterized by impairment in both global (abstract) and specific (motor-sensory) processing, as well as in efficient integration of these processes. This conclusion is in line with the view that integration of information processed in the cerebral cortex might depend on the dynamic formation and disassembling of synchronized neuronal assemblies, characterized by various frequency bands (Engel and Singer 2001;Palva et al 2005;Palva and Palva 2007;Babiloni et al 2009). …”

Section: Concluding Discussionsupporting

confidence: 86%

Toward operational architectonics of consciousness: basic evidence from patients with severe cerebral injuries

Fingelkurts

Bagnato

et al. 2011

Cogn Process

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Although several studies propose that the integrity of neuronal assemblies may underlie a phenomenon referred to as awareness, none of the known studies have explicitly investigated dynamics and functional interactions among neuronal assemblies as a function of consciousness expression. In order to address this question, EEG operational architectonics analysis (Fingelkurts and Fingelkurts 2001, 2008) was conducted in patients in minimally conscious (MCS) and vegetative states (VS) to study the dynamics of neuronal assemblies and operational synchrony among them as a function of consciousness expression. We found that in minimally conscious patients and especially in vegetative patients neuronal assemblies got smaller, their life span shortened and they became highly unstable. Furthermore, we demonstrated that the extent/volume and strength of operational synchrony among neuronal assemblies was smallest or even absent in VS patients, intermediate in MCS patients, and highest in healthy fully conscious subjects. All findings were similarly observed in EEG alpha as well as beta1 and beta2 frequency oscillations. The presented results support the basic tenets of operational architectonics theory of brain-mind functioning and suggest that EEG operational architectonics analysis may provide an objective and accurate means of assessing signs of (un)consciousness in patients with severe brain injuries. Therefore, this methodological approach may complement the existing "gold standard" of behavioral assessment of this population of challenging patients and inform the diagnostic and treatment decision-making processes.

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Section: Concluding Discussionsupporting

confidence: 86%

Toward operational architectonics of consciousness: basic evidence from patients with severe cerebral injuries

Fingelkurts

Bagnato

et al. 2011

Cogn Process

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“…The full frequency directed transfer function (ffDTF) was significantly reduced in MCI [97] and AD patients [98] in comparison to control subjects, whereas DTF was only significantly reduced in AD patients [98]. In [109] directed transfer function (DTF) was applied to the EEG of amnesic MCI and AD patients; it was found that the parietal to frontal direction of the information flux was weaker in MCI and AD subjects, specifically for alpha and beta rhythms.…”

Section: Granger Causalitymentioning

confidence: 99%

Diagnosis of Alzheimers Disease from EEG Signals: Where Are We Standing?

Dauwels¹,

Vialatte²,

Cichocki³

2010

CAR

377

188

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This paper reviews recent progress in the diagnosis of Alzheimer's disease (AD) from electroencephalograms (EEG). Three major effects of AD on EEG have been observed: slowing of the EEG, reduced complexity of the EEG signals, and perturbations in EEG synchrony. In recent years, a variety of sophisticated computational approaches has been proposed to detect those subtle perturbations in the EEG of AD patients. The paper first describes methods that try to detect slowing of the EEG. Next the paper deals with several measures for EEG complexity, and explains how those measures have been used to study fluctuations in EEG complexity in AD patients. Then various measures of EEG synchrony are considered in the context of AD diagnosis.Also the issue of EEG pre-processing is briefly addressed. Before one can analyze EEG, it is necessary to remove artifacts due to for example head and eye movement or interference from electronic equipment. Pre-processing of EEG has in recent years received much attention. In this paper, several state-of-the-art pre-processing techniques are outlined, for example, based on blind source separation and other non-linear filtering paradigms.In addition, the paper outlines opportunities and limitations of computational approaches for diagnosing AD based on EEG. At last, future challenges and open problems are discussed.

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“…Numerous studies have reported decreased EEG synchrony in MCI and AD patients under resting conditions ("spontaneous EEG")(see, e.g., [19,33,[45][46][47][48][49][50][51][52][53][54][55][56][57][58]). More precisely, the statistical dependence between spontaneous EEG signals recorded from different channels seems to be generally lower in MCI and AD patients than in age-matched control subjects.…”

Section: Perturbations In Eeg Synchronymentioning

confidence: 99%

“…More precisely, the statistical dependence between spontaneous EEG signals recorded from different channels seems to be generally lower in MCI and AD patients than in age-matched control subjects. A large variety of measures have been applied to quantify this loss in statistical dependence, e.g., Pearson correlation coefficient [51], coherence [51,52,54], Granger causality [33,45,51], information-theoretic [58,51] and state space based synchrony measures [19,46,51,55,56], phase synchrony indices [19,51,53,54,57], and stochastic event synchrony [47][48][49][50][51]. In a recent study, the spatial distribution of EEG phase synchrony in AD patients has been investigated [60].…”

Section: Perturbations In Eeg Synchronymentioning

confidence: 99%