Increased risk for age-related impairment in visual attention associated with mild traumatic brain injury: Evidence from saccadic response times

Multimodal Neurocognitive Screening of Military Personnel With a History of Mild Traumatic Brain Injury Using the Bethesda Eye & Attention Measure

OBJECTIVE

To evaluate a neurocognitive eye tracking task, the Bethesda Eye & Attention Measure (BEAM), for use in cognitive screening of patients with a history of mild traumatic brain injury (TBI).

SETTING

US military TBI rehabilitation clinic.

DESIGN/PARTICIPANTS

Cross-sectional study of 191 military personnel receiving outpatient services related to history of mild TBI. Main measures: BEAM; neuropsychological screening measures of attention, processing speed, executive function, and memory.

RESULTS

Medium effect sizes were found for partial correlations (controlling for age) between key BEAM metrics and neuropsychological screening tests. Linear regression analyses demonstrated that BEAM saccadic eye movements and manual (button press) metrics each provided complementary value in measurement of cognitive performance, above and beyond effects of demographic factors and clinical characteristics.

CONCLUSION

This study provides initial support for the use of BEAM neurocognitive eye tracking in cognitive screening of adults with a history of mild TBI. BEAM saccadic metrics appear to be particularly well-suited for the assessment of visual attention. Study findings also highlight opportunities for greater cognitive sensitivity or testing efficiency that may be missed by tests measuring only one response modality at a time.

Clinical validation of an optimized multimodal neurocognitive assessment of chronic mild TBI

OBJECTIVE

Previous laboratory-based studies have shown that neurocognitive eye-tracking metrics are sensitive to chronic effects of mild traumatic brain injury (mTBI), even in individuals with normal performance on traditional neuropsychological measures. In this study, we sought to replicate and extend these findings in a military medical environment. We expected that metrics from the multimodal Fusion n-Back test would successfully distinguish chronic mTBI participants from controls, particularly eye movement metrics from the more cognitively challenging "1-Back" subtest.

METHODS

We compared performance of participants with chronic mTBI (n = 46) and controls (n = 33) on the Fusion n-Back test and a battery of conventional neuropsychological tests. Additionally, we examined test reliability and the impact of potential confounds to neurocognitive assessment.

RESULTS

Our results supported hypotheses; Fusion 1-Back metrics were successful in multimodal (saccadic and manual) classification of chronic mTBI versus control. In contrast, conventional neuropsychological measures could not distinguish these groups. Additional findings demonstrated the reliability of Fusion n-Back test metrics and provided evidence that saccadic metrics are resistant to confounding influences of age, intelligence, and psychiatric symptoms.

INTERPRETATION

The Fusion n-Back test could provide advantages in differential diagnosis for complex brain injury populations. Additionally, the rapid administration of this test could be valuable for screening patients in clinical settings where longer test batteries are not feasible.