Entropy Metrics Correlating with Higher Residual Functioning in Patients with Chronic Disorders of Consciousness

Visani, Elisa; Luria, Gianvittorio; Sattin, Davide; Sebastiano, Davide Rossi; Ferraro, Stefania; Panzica, Ferruccio; Leonardi, Matilde; Franceschetti, Silvana

doi:10.3390/brainsci12030332

Cited by 8 publications

(6 citation statements)

References 29 publications

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“…Our result consistently supports integrated information theory and further suggests that PLZC will perform better than LZC in correlation with the residual consciousness of DOC patients. The global LZC was observed in a recent study with LZC variation between VS/UWS and MCS presented only at the theta band [ 26 ]. The underlying reason for this may be explained by the rather rough coarse-graining procedure of the LZC.…”

Section: Discussionmentioning

confidence: 99%

EEG complexity correlates with residual consciousness level of disorders of consciousness

et al. 2023

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Background and objective Electroencephalography (EEG) and neuroimaging measurements have been highly encouraged to be applied in clinics of disorders of consciousness (DOC) to improve consciousness detection. We tested the relationships between neural complexity measured on EEG and residual consciousness levels in DOC patients. Methods Resting-state EEG was recorded from twenty-five patients with DOC. Lempel–Ziv complexity (LZC) and permutation Lempel–Ziv complexity (PLZC) were measured on the EEG, and their relationships were analyzed with the consciousness levels of the patients. Results PLZC and LZC values significantly distinguished patients with a minimally conscious state (MCS), vegetative state/unresponsive wakefulness syndrome (VS/UWS), and healthy controls. PLZC was significantly correlated with the Coma Recovery Scale-Revised (CRS-R) scores of DOC patients in the global brain, particularly in electrodes locating in the anterior and posterior brain regions. Patients with higher CRS-R scores showed higher PLZC values. The significant difference in PLZC values between MCS and VS/UWS was mainly located in the bilateral frontal and right hemisphere regions. Conclusion Neural complexity measured on EEG correlates with residual consciousness levels of DOC patients. PLZC showed higher sensitivity than LZC in the classification of consciousness levels.

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Section: Discussionmentioning

confidence: 99%

EEG complexity correlates with residual consciousness level of disorders of consciousness

et al. 2023

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“…Firstly, there is now substantial evidence to support the entropy brain principle, in terms of increased brain entropy in relation to the psychedelic state (Carhart-Harris et al, 2014), and other flexible mental states such as Rapid Eyes Movement Sleep (Lee et al, 2013) and dreaming (Nardelli et al, 2019), jazz improvisation (Simon, 2005), and deep meditation (Kumar et al, 2022;Li, Hu, Zhang and Zhang, 2011) -and reduced brain entropy under states of reduced consciousness such as deep sleep (Kung et al, 2022), the anaesthetized state (Fuentes et al, 2022) and disorders of consciousness (Visani et al, 2022). More specific support for REBUS can be found in perceptual changes under psychedelics (Kaiser and Gold, 1973), altered beliefs under (Safron, 2020) and after psychedelics (McGovern et al, 2022;Timmermann et al, 2021) as well as other trait changes (Aday et al, 2021) as well as decreased top-down processing seen through such metrics as travelling waves (Alamia et al, 2020), dynamic causal modelling (Muthukumaraswamy et al, 2013), and transfer entropy (Wang, Chen and Chen, 2022;Vicente et al, 2011) reduced hierarchical organisation under psychedelics (Girn et al 2022) and the flattening of the brain's energy landscape under (Singleton et al 2021) and after (Daws et al 2022) psychedelics.…”

Section: Neuroscience Of Psychedelics: Psychedelics As Destabilisers ...mentioning

confidence: 99%

Pattern Breaking: A Complex Systems Approach to Psychedelic Medicine

Hipólito¹,

Mago²,

Rosas³

et al. 2022

Preprint

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There is growing evidence for the safety and efficacy of psychedelic therapy in mental health care. What is less understood however, is how psychedelics act to yield therapeutic results. In this paper we propose that psychedelics act as destabilisers — both in a psychological and a neurophysiological sense. Our proposed framework builds on the ‘entropic brain’ hypothesis, according to which psychedelics increase the entropy of spontaneous cortical activity and, in parallel, the richness or depth of content of psychological experience. The so-called ‘RElaxed Beliefs Under pSychedelics’ (REBUS) model is a predictive-coding inspired extension to this hypothesis, which states that psychedelics’ entropic action is paralleled by a relaxation of prior assumptions. Here we adopt a complex systems theory (CST) perspective, proposing that psychedelics act as destabilisers of excessively reinforced fixed points — or ‘attractors’ — which translates as the breaking of excessively reinforced or overweighted patterns of thinking or behaving. Our CST approach explains how psychedelic-induced increases in brain entropy destabilise neurophysiological set-points that are synonymous with overweighted priors, thereby augmenting and enriching the account given by REBUS. We believe that this perspective helps inspire conceptualisations of psychedelic psychotherapy — bearing relevance both to the peak psychedelic experience and subsequent sub-acute period of potential recovery. We discuss implications for risk mitigation and treatment optimization in psychedelic medicine.

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“…Vegetative consciousness/unresponsive wakefulness syndrome patients always exhibited lower EEG complexity at the frontal than did MCS and healthy subjects ( Thul et al, 2016 ). It has been revealed through the approximate entropy, amplitude coalition entropy and spectral entropy ( Gosseries et al, 2011a ; Piarulli et al, 2016 ; Liu et al, 2021 ; Visani et al, 2022 ).…”

Section: Evidence Of Frontal Role In Docmentioning

confidence: 99%

Frontal and parietal lobes play crucial roles in understanding the disorder of consciousness: A perspective from electroencephalogram studies

Liu

Bai

2023

Front. Neurosci.

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BackgroundElectroencephalogram (EEG) studies have established many characteristics relevant to consciousness levels of patients with disorder of consciousness (DOC). Although the frontal and parietal brain regions were often highlighted in DOC studies, their electro-neurophysiological roles in constructing human consciousness remain unclear because of the fragmented information from literatures and the complexity of EEG characteristics.MethodsExisting EEG studies of DOC patients were reviewed and summarized. Relevant findings and results about the frontal and parietal regions were filtered, compared, and concluded to clarify their roles in consciousness classification and outcomes. The evidence covers multi-dimensional EEG characteristics including functional connectivity, non-linear dynamics, spectrum power, transcranial magnetic stimulation-electroencephalography (TMS-EEG), and event-related potential.Results and conclusionElectroencephalogram characteristics related to frontal and parietal regions consistently showed high relevance with consciousness: enhancement of low-frequency rhythms, suppression of high-frequency rhythms, reduction of dynamic complexity, and breakdown of networks accompanied with decreasing consciousness. Owing to the limitations of EEG, existing studies have not yet clarified which one between the frontal and parietal has priority in consciousness injury or recovery. Source reconstruction with high-density EEG, machine learning with large samples, and TMS-EEG mapping will be important approaches for refining EEG awareness locations.

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Entropy Metrics Correlating with Higher Residual Functioning in Patients with Chronic Disorders of Consciousness

Cited by 8 publications

References 29 publications

EEG complexity correlates with residual consciousness level of disorders of consciousness

EEG complexity correlates with residual consciousness level of disorders of consciousness

Pattern Breaking: A Complex Systems Approach to Psychedelic Medicine

Frontal and parietal lobes play crucial roles in understanding the disorder of consciousness: A perspective from electroencephalogram studies

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