Research In Action

Research In Action

concussion eye exam
Saccades and Gaze Stability Assessments Improve Concussion Detection
April 15, 2021

The Visio-Vestibular Examination (VVE) is a battery of several clinical assessments that is used to support the diagnosis of concussion in the sports medicine specialty care setting. The different exams identify visual and vestibular (e.g. balance) deficits that can indicate that a concussion has occurred following a head injury.

Over the past few years the team at the Minds Matter Concussion Program has systematically conducted research to determine the utility and ease of administration of the VVE across different practice settings; specifically, we are pioneering its use outside of the sports medicine world, such as in primary, emergency and urgent care. Our previous work has shown that children who receive a VVE upon their initial evaluation are more likely to receive a concussion diagnosis, which is important since earlier diagnosis is associated with improved outcomes.

Why the VVE?

There is emerging evidence that visual- and vestibular-related impairments are common after concussion and are an important part of concussion evaluation, as they have been linked to worse outcomes, including delayed return to school and sport.

Assessing Saccades and Gaze Stability As Important Diagnostic Markers of Concussion

Our latest paper was just published in Clinical Journal of Sports Medicine. The study focused on saccades and gaze stability tests, two tests of visual and vestibular function. The evaluation for saccadic eye movements assesses rapid eye movements in two different planes (horizontal and vertical) between two fixed objects to see if symptoms are provoked. The gaze stability test (also called the angular vestibulo-ocular reflex) assesses if head movement, while eyes are fixed on a stationary object, provokes symptoms. Each test is conducted with a fixed number of repetitions to assess for symptom provocation.

We evaluated the discriminatory ability of saccades and gaze stability testing at different repetition increments to determine the optimal number of repetitions to differentiate adolescent athletes with concussion from those without concussion. As originally described by our colleagues in Pittsburgh in the vestibular oculomotor screening exam, symptoms are assessed after performing 10 repetitions of these four tests (saccades and gaze stability in both the horizontal and vertical plane). However, this study of 138 adolescent athletes (69 with concussion, 69 without concussion) showed that raising the number of repetitions to 20 significantly increased the sensitivity of the test. When combining the four tests, we found discriminatory ability was maximized with a cut-off of 20 repetitions.

By increasing the number of repetitions of the test, we are able to create a more demanding task, one that provides a more rigorous “stress test” for the brain and can help to identify subtle deficits that may go unnoticed in regular clinical assessments, as well as avoid the pitfall of a ceiling effect with only 10 repetitions. Overall, the results of this particular study suggest that increasing task difficulty of these clinical assessments can improve their detection of visio-vestibular deficits in concussed youth and more accurately diagnose concussion across any clinical setting.

Through this line of visio-vestibular-focused research, we have demonstrated that the VVE series of assessments is feasible for clinicians to perform across various care settings, which is especially important as our prior work has shown that most concussed children are diagnosed in primary care.

Watch Dr. Daniel Corwin demonstrate how to administer the VVE: