Traumatic brain injury and vestibulo-ocular function: current challenges and future prospects

Abstract

Normal function of the vestibulo-ocular reflex (VOR) coordinates eye movement with head movement, in order to provide clear vision during motion and maintain balance. VOR is generated within the semicircular canals of the inner ear to elicit compensatory eye movements, which maintain stability of images on the fovea during brief, rapid head motion, otherwise known as gaze stability. Normal VOR function is necessary in carrying out activities of daily living (eg, walking and riding in a car) and is of particular importance in higher demand activities (eg, sports-related activities). Disruption or damage in the VOR can result in symptoms such as movement-related dizziness, blurry vision, difficulty maintaining balance with head movements, and even nausea. Dizziness is one of the most common symptoms following traumatic brain injury (TBI) and is considered a risk factor for a prolonged recovery. Assessment of the vestibular system is of particular importance following TBI, in conjunction with oculomotor control, due to the intrinsic neural circuitry that exists between the ocular and vestibular systems. The purpose of this article is to review the physiology of the VOR and the visual-vestibular symptoms associated with TBI and to discuss assessment and treatment guidelines for TBI. Current challenges and future prospects will also be addressed.

Prevalence of Vestibular Dysfunction in Children With Neurological Disabilities: A Systematic Review

“…The authors mentioned that the widely distributed central and peripheral components of the vestibular system makes it vulnerable to the translated forces experienced during TBIs. Despite extensive studies being published on the prevalence of vestibular dysfunction due to TBI in adults (66)(67)(68), there is a substantial gap in literature concerning the pediatric population. We, in this present review, included only three studies evaluating the prevalence of vestibular dysfunction due to TBI.…”

Clinical Assessments of Balance in Adults with Concussion: An Update

“…Abnormalities in the rapid eye function include increased latency to eye movement (165 ms concussion vs. 149 ms control) when a stimulus is presented and an increased error distance (1.11 cm concussion vs. 0.86 cm control) during rapid eye movement tasks. 60,61 Cranial nerve issues may be present due to asymmetrical eye movements during rapid eye movements. 60 Further rapid eye movement abnormalities are noted when slow object tracking is performed in the manner of frequent update rapid eye movements onto the object of focus.…”

“…60,61 Cranial nerve issues may be present due to asymmetrical eye movements during rapid eye movements. 60 Further rapid eye movement abnormalities are noted when slow object tracking is performed in the manner of frequent update rapid eye movements onto the object of focus. 60 Previous literature has reported that patients suffering from a concussion have an increased amount of errors and deficits in the prediction of targets during object tracking.…”

“…60 Further rapid eye movement abnormalities are noted when slow object tracking is performed in the manner of frequent update rapid eye movements onto the object of focus. 60 Previous literature has reported that patients suffering from a concussion have an increased amount of errors and deficits in the prediction of targets during object tracking. 62 Recently, concussed individuals have been noted to have increased gaze velocities (232 degrees per second) compared to healthy controls (208 degrees per second) as the angular velocity of a circular stimulus increased.…”

Vestibular system dysfunction in patients after mild traumatic brain injury

“…In the case of mild head injury, the symptoms of the post-concussion syndrome, including those of the balance system, may last for a year or even longer in 10 -15% of patients, and this percentage increases to 28% in moderate traumatic injuries [1,21]. Dizziness after brain injury is also a risk factor for a prolonged recovery [22].…”