ИСТИНА

Introduction Disorders of consciousness (DOC) constitute some of the most devastating neurological conditions [1]. Understanding their neuronal basis can help improve the accuracy of diagnosis, indicate potential targets for therapeutic interventions and provide insights into the organization of normal consciousness. A number of neural correlates of DOC have been found using different modalities of brain activity measurement [1]. We here aimed at finding the aspects of fMRI-based functional connectivity that differentiate unresponsive wakefulness syndrome (UWS) and the minimally conscious state (MCS) from each other and from the normal condition. Methods For 22 patients (9 MCS, 13 UWS) and 14 healthy subjects, resting state fMRI was performed (3T, resolution 3.0 x 3.0 x 3.0 mm3, TR = 2.4 s, 190 scans). ROI-to-ROI connectivity for an atlas of 278 brain areas was computed using the Conn toolbox. Several connectivity characteristics were compared between the healthy and patient groups, as well as between UWS and MCS. Among them, two novel measures of connectome disruption were introduced, which quantify the degree of similarity of an individual connectivity matrix with the corresponding average matrix from healthy subjects [2]. Results Patients were shown to have reduced connectivity in most resting state networks and disrupted patterns of relative connection strengths as compared to healthy subjects. UWS and MCS patients differed in the patterns formed by a relatively small number of strongest positive correlations selected by thresholding (Fig. 1). Discussion and Conclusions The results suggest that the strong positive correlations between the functional activities of specific brain areas observed in healthy individuals may be critical for consciousness and be an important target of disruption in disorders of consciousness. Further research, including theoretical models, is needed to understand the possible role of these correlations in conscious information processing. Acknowledgement: The study was supported by the Russian Science Foundation under grant 16-15-00274. References [1] J.T. Giacino, J.J. Fins, S. Laureys, N.D. Schiff, Disorders of consciousness after acquired brain injury: the state of the science, Nature Reviews Neurology, 10: 99–114 (2014), doi:10.1038/nrneurol.2013.279. [2] D.O. Sinitsyn, L.A. Legostaeva, E.I. Kremneva et al., Degrees of functional connectome abnormality in disorders of consciousness, Human brain mapping, DOI: 10.1002/hbm.24050.