Quantitative evaluation of the consciousness level of patients in a vegetative state using virtual reality and an eye-tracking system: A single-case experimental design study

ABSTRACT

It is important to distinguish patients in a minimally conscious state (MCS) from patients in a vegetative state (VS) when assessing disorders of consciousness (DOC) as prognosis, selection of therapy, and drug treatment could differ accordingly. Clinical evaluation of a patient’s eye movements, such as visual startle, visual fixation, and visual pursuit, provides valuable evidence but is often subject to misdiagnosis. To minimize such misdiagnosis caused by human judgment, a virtual reality (VR) technology-based quantitative assessment method with an eye-tracking system is proposed in this study. The new VR system presented 3 stimuli to 20 healthy participants, and visual response data were recorded to define valid responses to each stimulus. Further, the newly defined stimuli were presented to five chronic patients in VS, and the system classified three of them as showing visual fixations that could not be verified through clinical assessment beforehand. The proposed system, as verified through such experimentation, suggests quantitative and objective evaluation methods for examining three visual functions of patients with DOC.

KEYWORDS:

• Virtual reality
• Eye tracking
• Disorders of consciousness
• Coma recovery scale
• Visual function

Acknowledgments

We would like to thank Editage (www.editage.co.kr) for editing and reviewing this manuscript for the English language.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported by the Rehabilitation Research & Development Support Program* (#NRC RSP-2019009), National Rehabilitation Center, Ministry of Health and Welfare, Korea.