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Brain dynamic functional connectivity in patients with disorders of consciousness

Ever since the proposal that brain activity is organized into networks of coherent activity in the framework of functional connectivity (FC, [1]), a great amount of research has been conducted to characterize these networks, their inter-relations, and their differential participation in sensory-motor and cognitive processes, as well as their alteration in brain states such as pathological diseases, sleep, etc. The main techniques to study FC are functional magnetic resonance imaging (fMRI) and positron emition tomography (PET), but it has also been described using other techniques, such as MEG and EEG [2]. The classic approach to obtain FC networks is to calculate the correlation between the low-pass filtered time series of brain nodes (i.e., voxels, anatomical areas, etc.) along the scanning period. In this way the studies on FC commonly assume a rather static correlation pattern. Although such studies unraveled important features of brain large-scale functioning, FC is in fact highly variable in time and across subjects [3]. Recent work digs deeper into this variability and brings up important caveats to many previous assumptions. For instance, new findings suggest that networks may reorganize in time, weakening their intra-network connectivity strengh and enforcing the inter-network connectivities, and that there may exist discrete states of multistability over time [4].

In the present work the dynamic functional connectivity was analyzed in a group of patients with disorders of consciousness (DOC) as well as in healthy subjects, during a resting state (RS) fMRI paradigm. The correlation matrices (R) between predefined brain areas were obtained in sequential time windows. The temporal variability of different metrics of the R matrices was examined. Furthermore, main components (i.e., hidden states of frequent brain configurations) were identified from DOC or Control groups' R temporal series by employing singular value decomposition (SVD). SVD is a dimensionality reduction technique that allows for obtaining a latent correlation structure model, and has been previously applied by Leonardi et al. [5] to RS fMRI data. In the present work we investigated whether the main SVD components differ between DOC and Control groups and in which temporal manner. Preliminary results show that the main components present dissimilarities between the groups in specific brain areas. Furthermore, the temporal variation of the largest eigenvalue (that is interpreted as the collective motion of all areas) of the R matrices is different in DOC compared to Control group.

The results may contribute to the understanding of the process of consciousness in so far as brain dynamic functionality and have potential impact in the understanding of consciousness disorder.

References

  1. Friston KJ: Functional and effective connectivity: a review. Brain Connect. 2011, 1: 13-36. 10.1089/brain.2011.0008.

    Article  PubMed  Google Scholar 

  2. de Pasquale F, Della Penna S, Snyder AZ, Lewis C, Mantini D, Marzetti L, Belardinelli P, Ciancetta L, Pizzella V, Romani GL, Corbetta M: Temporal dynamics of spontaneous MEG activity in brain networks. PNAS. 2011, 107 (13): 6040-5.

    Article  Google Scholar 

  3. Honey CJ, Sporns O, Cammoun L, Gigandet X, Thiran JP, Meuli R, Hagmann P: Predicting human brain functional connectivity from structural connectivity. PNAS. 2008, 106 (6): 2035-40.

    Article  Google Scholar 

  4. Hutchison RM, Womelsdorf T, Allen EA, Bandettini PA, Calhoun VD, Corbetta M, Della Penna S, Duyn JH, Glover GH, Gonzalez-Castillo J, et al: Dynamic functional connectivity: promise, issues, and interpretations. Neuroimage. 2013, 80: 360-378.

    Article  PubMed  Google Scholar 

  5. Leonardi N, Richiardi J, Van De Ville D: Functional connectivity eigennetworks reveal different brain dynamics in multiple sclerosis patients. IEEE 10th International Symposium on Biomedical Imaging:From Nano to Macro. 2013, San Francisco, USA

    Google Scholar 

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Correspondence to Verónica Mäki-Marttunen.

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This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

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Mäki-Marttunen, V. Brain dynamic functional connectivity in patients with disorders of consciousness. BMC Neurosci 15 (Suppl 1), P105 (2014). https://0-doi-org.brum.beds.ac.uk/10.1186/1471-2202-15-S1-P105

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  • DOI: https://0-doi-org.brum.beds.ac.uk/10.1186/1471-2202-15-S1-P105

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