Consciousness Detection in a Complete Locked-in Syndrome Patient through Multiscale Approach Analysis

Shang-Ju Wu; Nicoletta Nicolaou; Martin Bogdan

doi:10.3390/e22121411

Consciousness Detection in a Complete Locked-in Syndrome Patient through Multiscale Approach Analysis

Entropy (Basel). 2020 Dec 15;22(12):1411. doi: 10.3390/e22121411.

Authors

Shang-Ju Wu¹, Nicoletta Nicolaou^{2

3}, Martin Bogdan¹

Affiliations

¹ Neuromorphic Information Processing, Leipzig University, Augustusplatz 10, 04109 Leipzig, Germany.
² Department of Basic and Clinical Sciences, University of Nicosia Medical School, 93 Agiou Nikolaou Street, Engomi 2408, Nicosia, Cyprus.
³ Centre for Neuroscience and Integrative Brain Research (CENIBRE), University of Nicosia Medical School, 93 Agiou Nikolaou Street, Engomi 2408, Nicosia, Cyprus.

Abstract

Completely locked-in state (CLIS) patients are unable to speak and have lost all muscle movement. From the external view, the internal brain activity of such patients cannot be easily perceived, but CLIS patients are considered to still be conscious and cognitively active. Detecting the current state of consciousness of CLIS patients is non-trivial, and it is difficult to ascertain whether CLIS patients are conscious or not. Thus, it is important to find alternative ways to re-establish communication with these patients during periods of awareness, and one such alternative is through a brain-computer interface (BCI). In this study, multiscale-based methods (multiscale sample entropy, multiscale permutation entropy and multiscale Poincaré plots) were applied to analyze electrocorticogram signals from a CLIS patient to detect the underlying consciousness level. Results from these different methods converge to a specific period of awareness of the CLIS patient in question, coinciding with the period during which the CLIS patient is recorded to have communicated with an experimenter. The aim of the investigation is to propose a methodology that could be used to create reliable communication with CLIS patients.

Keywords: Poincaré plot; completely locked-in state (CLIS); consciousness; electrocorticography (ECoG); multiscale approach; permutation entropy; sample entropy.