An Auditory BCI System for Assisting CRS-R Behavioral Assessment in Patients with Disorders of Consciousness.

Jun Xiao,Yuanqing Li,Shenglin Lu,Ronghao Yu,Tianyou Yu,Ningmeng Huang,Qiuyou Xie,Yanbin He

doi:10.1038/srep32917

Abstract

The Coma Recovery Scale-Revised (CRS-R) is a consistent and sensitive behavioral assessment standard for disorders of consciousness (DOC) patients. However, the CRS-R has limitations due to its dependence on behavioral markers, which has led to a high rate of misdiagnosis. Brain-computer interfaces (BCIs), which directly detect brain activities without any behavioral expression, can be used to evaluate a patient’s state. In this study, we explored the application of BCIs in assisting CRS-R assessments of DOC patients. Specifically, an auditory passive EEG-based BCI system with an oddball paradigm was proposed to facilitate the evaluation of one item of the auditory function scale in the CRS-R – the auditory startle. The results obtained from five healthy subjects validated the efficacy of the BCI system. Nineteen DOC patients participated in the CRS-R and BCI assessments, of which three patients exhibited no responses in the CRS-R assessment but were responsive to auditory startle in the BCI assessment. These results revealed that a proportion of DOC patients who have no behavioral responses in the CRS-R assessment can generate neural responses, which can be detected by our BCI system. Therefore, the proposed BCI may provide more sensitive results than the CRS-R and thus assist CRS-R behavioral assessments.

Highlights

The Coma Recovery Scale-Revised (CRS-R) is a consistent and sensitive behavioral assessment standard for disorders of consciousness (DOC) patients
Amplitude variation was rarely observed for the standard stimuli, and this finding is consistent with the physiological principles of mismatch negativity (MMN) and P300 presented in ref
It is believed that if a patient is able to follow an instruction to imagine his/her left/right-hand movement or gaze at different visual stimuli, he/she is conscious. This method could help to reduce the possibility of misdiagnosis of those DOC patients who have difficulty exhibiting any behavioral response to external stimuli

Summary

Introduction

The Coma Recovery Scale-Revised (CRS-R) is a consistent and sensitive behavioral assessment standard for disorders of consciousness (DOC) patients. We explored the application of BCIs in assisting CRS-R assessments of DOC patients. Several behavioral assessment methods have been designed for assessments of brain-damaged patients suffering from disorders of consciousness (DOC), which generally include coma, vegetative state (VS), minimally conscious state (MCS) and emergence from MCS (EMCS). Among these methods, the Glasgow Coma Scale (GCS), the Coma Recovery Scale-Revised (CRS-R), the Full Outline of UnResponsiveness (FOUR), and the Wessex Head. Correspondence and requests for materials should be addressed to R.Y.

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