Alpha rhythm operational architectonics in the continuum of normal and pathological brain states: Current state of research

Neurorehabil Neural Repair

Bagnato

et al. 2013

Self Cite

The result of this preliminary study demonstrates that structural strategy of EEG analysis is better suited for providing prognosis of consciousness recovery than existing methods of clinical assessment and of conventional EEG. Our results may be a starting point for developing reliable prognosticators in patients who are in a vegetative state, with the potential to improve their day-to-day management, quality of life, and access to early interventions.

Section: Potential Role Of Electroencephalogrammentioning

confidence: 99%

Prognostic Value of Resting-State Electroencephalography Structure in Disentangling Vegetative and Minimally Conscious States

Neurorehabil Neural Repair

Bagnato

et al. 2013

Self Cite

“…57 This OA strategy of EEG analysis has been validated in a number of electrophysiological, cognitive, and clinical studies and is proven to be robust, consistent, and statistically reliable. 55,66,67 The OA theory predicts that both low and high levels of operational synchrony among neuronal assemblies can result in a dramatic fading of consciousness. 57 In the first case, consciousness is likely to vanish in the presence of many small, short-lived, and highly unstable neuronal assemblies that perform their operations totally independently of one another (functional disconnection), while in the second case a state of hypersynchrony of operations of large, long-lived, and hyperstable neuronal assemblies is also likely to lead to the vanishing of consciousness.…”

Section: Introductionmentioning

confidence: 99%

Dissociation of Vegetative and Minimally Conscious Patients Based on Brain Operational Architectonics

Bagnato

et al. 2013

Clin EEG Neurosci

Self Cite

Discrimination between patients in vegetative (VS) and minimally conscious state (MCS) is currently based upon the behavioral gold standard. Behavioral assessment remains equivocal and difficult to interpret as evidence for the presence or absence of consciousness, resulting in possible clinical misdiagnosis in such patients. Application of an operational architectonics (OA) strategy to electroencephalogram (EEG) analysis reveals that absence of consciousness in patients in VS is paralleled by significant impairment in overall EEG operational architecture compared to patients in MCS: neuronal assemblies become smaller, their life span shortened, and they became highly unstable and functionally disconnected (desynchronized). However, in a previous study, patients with different brain damage etiologies were intermixed. Therefore, the goal of the present study was to investigate whether the application of OA methodology to EEG could reliably dissociate patients in VS and MCS independent of brain damage etiology. We conclude that the observed EEG OA structure impairment in patients in VS and partial preservation in patients in MCS is a marker of consciousness/unconsciousness rather than physiological damage. Results of this study may have neuroscientific, clinical, and ethical implications.

“…Decreased repertoires size of EEG oscillatory states during neuropsychopathologic conditions may reflect alteration in neuronal assemblies functioning. This suggestion is supported by an earlier study which demonstrated that the size, stability and functional life-span of neuronal assemblies were increased and reached “true” pathological values in depression, opioid abuse and abstinence pathological conditions when compared with the healthy reference functional state [113]. By “ true ” pathological values we mean the values which are outside the boundaries of variability of healthy resting state with closed eyes.…”

Section: Discussionmentioning

confidence: 52%

“…This supposition is in line with the works of Thatcher and John [108], Herscovitch [109], Arieli et al [110], Tsodyks et al [111], Raichle et al [112], Raichle and Snyder [99] and others who demonstrated a highly organized intrinsic functional activity during a resting state i.e., activity which is not directly related to identifiable sensory or motor events. Recent support for this view came from Fingelkurts and Fingelkurts study [113] which presented evidence that the resting state with eyes closed is characterised by dynamic functioning of relatively large, but relatively short-lived neuronal assemblies and certain level of functional connectivity among them.…”

Section: Discussionmentioning

confidence: 99%

EEG Oscillatory States: Universality, Uniqueness and Specificity across Healthy-Normal, Altered and Pathological Brain Conditions

2014

PLoS ONE

Self Cite

For the first time the dynamic repertoires and oscillatory types of local EEG states in 13 diverse conditions (examined over 9 studies) that covered healthy-normal, altered and pathological brain states were quantified within the same methodological and conceptual framework. EEG oscillatory states were assessed by the probability-classification analysis of short-term EEG spectral patterns. The results demonstrated that brain activity consists of a limited repertoire of local EEG states in any of the examined conditions. The size of the state repertoires was associated with changes in cognition and vigilance or neuropsychopathologic conditions. Additionally universal, optional and unique EEG states across 13 diverse conditions were observed. It was demonstrated also that EEG oscillations which constituted EEG states were characteristic for different groups of conditions in accordance to oscillations’ functional significance. The results suggested that (a) there is a limit in the number of local states available to the cortex and many ways in which these local states can rearrange themselves and still produce the same global state and (b) EEG individuality is determined by varying proportions of universal, optional and unique oscillatory states. The results enriched our understanding about dynamic microstructure of EEG-signal.