Vestibular-ocular reflex dysfunction following mild traumatic brain injury: A narrative review

Mild traumatic brain injury (mTBI) is a prevalent injury which occurs across many populations, including children and adolescents, athletes, military personnel, and the elderly. mTBI can result in various subjective symptoms and clinical deficits, such as abnormalities to the vestibulo-ocular reflex (VOR). Over 50% of individuals with mTBI are reported to have VOR abnormalities, which strongly contribute to feelings of dizziness and unsteadiness. Dizziness is a strong predictor for prolonged recovery following mTBI and is additionally linked with mental health difficulties and functional limitations affecting likelihood of return to work. Early diagnosis, and subsequent treatment, of VOR deficits following mTBI may greatly improve recovery outcomes and a patient's quality of life, but a thorough comprehension of the related pathophysiology is necessary to understand the assessments used to diagnose VOR abnormalities. Therefore, the purpose of this article is i) provide readers with an introduction on the VOR physiology to facilitate understanding about mTBI-related abnormalities, and ii) to discuss current assessments that are commonly used to measure VOR function following mTBI. As the VOR and oculomotor (OM) systems are heavily linked and often work in tandem, discussion of the relevant aspects of the OM system is also provided.