The use of oculomotor, vestibular, and reaction time tests to assess mild traumatic brain injury (mTBI) over time

Abstract

Objectives: The objective of this work is to examine the outcomes of a set of objective measures for evaluating individuals with minor traumatic brain injury (mTBI) over the sub-acute time period. These methods involve tests of oculomotor, vestibular, and reaction time functions. This work expands upon published work examining these test results at the time of presentation.

Study design: This study is a prospective age- and sex-matched controlled study.

Materials and methods: The subject group was composed of 106 individuals with mTBI and 300 age- and sex-matched controls without a history of mTBI. All individuals agreeing to participate in the study underwent a battery of oculomotor, vestibular, and reaction time tests (OVRT). Those subjects with mTBI underwent these tests at presentation (within 6 days of injury) and 1 and 2weeks post injury. These outcomes were compared to each other over time as well as to results from the controls that underwent 1 test session.

Results: Six measures from 5 tests can classify the control and mTBI during Session 1 with a true positive rate (sensitivity) of 84.9% and true negative rate (specificity) of 97.0%. Patterns of abnormalities changed over time in the mTBI group and overall normalized in a subset of individuals at the third (final) testing session.

Conclusions: We describe an objective and effective second generation testing algorithm for diagnosing and following the prognosis of mTBI/concussion. This testing paradigm will allow investigators to institute better treatments and provide more accurate return to activity advice.

Level of evidence: 3.

Keywords: Concussion; Point of Injury Testing; Vestibular Disorders; mTBI.

Figure 1

Example of the saccade main sequence from a control subject. The fitted relationships are shown in blue for the left eye and red for the right eye. By convention, the rightward direction is positive. The average of the absolute values of the areas under the rightward and leftward curves was calculated as a metric of saccade main sequence performance.

Figure 2

Cumulative distribution functions for tests that predicted mTBI status during the acute testing period (Session 1). The 5% and 1% points for the control population are indicated by vertical lines. mTBI = minor traumatic brain injury.

Figure 3

Cumulative Session 3 distribution functions of individual test metrics from subjects with mTBI during Session 1. The subjects with Session 3 mTBI‐positive logistic regression scores are plotted in red and subjects with mTBI‐negative scores in blue. The Control group cumulative distributions functions are plotted for comparison. mTBI = minor traumatic brain injury.

Figure 4

Cumulative distribution functions after mTBI of the area under the saccadic main sequence and the VOR phase angle at 0.64 Hz horizontal oscillation. Note the persistence of an increased proportion of outliers during Session 3. mTBI = minor traumatic brain injury, VOR = vestibulo‐ocular reflex.