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Updated: Jul 11, 2026
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Assessment and Communication for People with Disorders of Consciousness
Published on: August 1, 2017
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Covert Tracking to Immersive Stimuli in Traumatic Brain Injury Subjects With Disorders of Consciousness
Gabriela Aklepi1,2, Brian Manolovitz1, Linda E Robayo3,4
1Department of Neurology, University of Miami, Miami, Florida, USA.
Journal of Neurotrauma
|August 25, 2023
Summary
Video eye-tracking (VET) can identify covert tracking in traumatic brain injury (TBI) patients, improving coma misclassification. This objective tool shows potential for assessing responsiveness and predicting recovery in unresponsive TBI subjects.
Area of Science:
- Neuroscience
- Clinical Neurology
- Biomedical Engineering
Background:
- Clinician-dependent eye tracking assessments can lead to misclassification of coma in traumatic brain injury (TBI) patients.
- Objective methods are needed to accurately assess responsiveness and predict recovery in individuals with TBI.
- Subtle visual tracking may be missed during bedside clinical examinations.
Purpose of the Study:
- To investigate the utility of video eye-tracking (VET) in detecting covert visual tracking in unresponsive TBI subjects.
- To compare VET findings with clinical assessments (Coma Recovery Scale-Revised) and neurological imaging (EEG, MRI).
- To evaluate the correlation between VET-detected tracking and patient recovery at 6- and 12-month follow-ups.
Main Methods:
- Recruited 20 healthy volunteers and 10 unresponsive TBI subjects.
- Recorded eye movements using VET in response to videos with and without audio.
- Defined tracking as visual fixation and gaze movement following stimuli; classified subjects as 'covert tracking', 'overt tracking', or 'no tracking'.
- Utilized a k-nearest neighbors model for computational tracking identification.
- Assessed thalamocortical connectivity (EEG) and structural integrity (MRI).
Main Results:
- Three TBI subjects showed 'covert tracking' (VET only), two showed 'overt tracking' (VET and clinical), and five showed 'no tracking'.
- 13% of trials met 'covert tracking' criteria via VET; a k-nearest approach identified 17% as 'covert tracking'.
- Subjects with tracking exhibited higher thalamocortical connectivity and less injury in the eye-tracking network.
- 2/3 'covert' and all 'overt' tracking subjects recovered consciousness, compared to only 2 'no tracking' subjects.
Conclusions:
- Video eye-tracking (VET) can objectively detect covert visual tracking in unresponsive TBI patients, potentially reducing coma misclassification.
- Immersive video stimuli with VET offer a promising tool for assessing subtle responsiveness in TBI.
- VET findings correlate with neurological connectivity and predict long-term recovery of consciousness.
