A BCI system for assisting visual fixation assessment in behavioral evaluation of patients with disorders of consciousness

Abstract

Visual fixation is an item of the Coma Recovery Scale-Revised (CRS-R), it is difficult to be detected by clinicians using the behavioral scales because of fluctuations of arousal level and the presence of motor impairment in disorders of consciousness (DOC) patients. Brain-computer interfaces (BCIs), which directly detect brain response without any behavioral expression, can be used to evaluate a patient's response to the stimuli. In this study, we explored the application of a 4-choice visual BCI in assisting visual fixation assessment of DOC patients. The results obtained from three patients indicated that one locked-in syndrome (LIS) patient showed visual fixation with the BCI assessment while exhibit higher visual function with the CRS-R assessment. The other two patients did not show any response to visual fixation with BCI assessment. The result revealed that EEG based BCI could detect brain response to the evaluation item of CRS-R in DOC patients. Therefore, the proposed BCI may provide a promising method for more objective result and thus assist CRS-R behavioral assessment.