Introduction: The World Health Organization predicts that by 2020 traumatic brain injuries (TBI) will be one of the most common causes of death and persistent injuries worldwide. Visual and vestibular deficits are particularly prevalent following TBI. Due to limitations of current assessment techniques, these deficits often go unnoticed by clinicians. The purpose of this study was to identify alterations in oculomotor, vestibular, and dynamic visual attention that occur following TBI and to investigate whether novel technological assessments would improve clinicians’ abilities to detect these TBI-induced deficits.
Methods: A convenience sample of ten participants who had suffered a severe traumatic brain injury between the ages of 18-50 years were invited to participate. This case series, feasibility and validation study is part of a transnational collaborative research program evaluating vestibulo-ocular deficits across all ages and the TBI severity spectrum (with sites in Calgary, Montreal, Paris, and Tel-Aviv). The Quality of Life after Brain Injury (QOLIBRI), Post-Concussion Symptom Inventory (PCSI), and Dizziness Handicap Inventory (DHI) questionnaires were administered. All participants underwent a neurological and cervical exam as well as clinical and technological oculomotor, vestibular, and balance assessments. The Neurotracker was used to assess dynamic visual attention. All assessments were performed as soon as possible once medically cleared for rehabilitation. Descriptive statistics were run for demographic information and primary outcome measures.
Results: Ten inpatients (9 males; 1 female) with a median age of 37.67 years (IQR 31.71-46.90 years) with severe TBI in Calgary, Alberta, Canada have completed the assessments. The participants had a median of 14.00 years of education (IQR 13.00-15.25 years). Median time since injury was 39.12 days (IQR 25.85- 56.03 days) with a median Glasgow Coma Scale score thirty minutes post-injury of 4 (IQR 3-5.5). 7/10 reported increased balance difficulties and 5/10 participants reported increased visual problems post-injury on the PCSI. 8/10 participants reported dizziness on the DHI with a median score of 22 (IQR 3-28). Cervical spine fracture, poor static visual acuity, facial fractures, skull sensitivity and orthopedic injuries limited which tests could be performed. Primary outcome measures of clinical versus technological assessments aligned in 1/6 for vestibular (clinical dynamic visual acuity test, InVision dynamic visual acuity test), 6/9 for oculomotor (clinical saccade test, Otometrics saccade test), and 7/9 for balance (Balance Error Scoring System, National Institutes of Health Toolbox Standing Balance Test). Median Neurotracker threshold score was 0.58 m/s (IQR 0.07-0.78).
Conclusion: Preliminary analyses suggest that technological evaluation of vestibulo-ocular deficits following TBI extends current clinical assessments. Limitations to testing included cervical spine fracture, poor static visual acuity, facial fractures, skull sensitivity and orthopedic injuries. Further research is required to investigate the technological measures for assessment of vestibulo-ocular impairments in the adult severe TBI population.

Comparison of Clinical and Technological Vestibular and Visual Assessments in Moderate/Severe Traumatic Brain Injury Patients