Utility of the Brain Gauge in traumatic brain injury: Results of the Al Asad missile exposure traumatic brain injury and health implications study

Abstract: INTRODUCTION: Blast exposure is responsible for the great majority of Traumatic Brain Injury (TBI) in deployed military service members (SMs). More rapid and reliable methods of diagnosis of blast TBI are needed. The Brain Gauge has been touted as an option, but published reports have had mixed results. MATERIALS AND METHODS: A review of a case series of 15 U.S. SMs (2 females) with TBI from incoming missiles fired at Al Asad Air Force Base, Iraq, on January 8, 2020. All had medical evacuation to Landstuhl Regional Medical Center (LRMC), Germany where the Brain Gauge was administered; 10 of 15 also repeat the Brain Gauge 4-5 days later. Performance on the Brain Gauge was compared with other assessments conducted at LRMC. In addition, Brain Gauge results from this cohort were compared with those from pertinent controls: 30 active duty U.S. Navy male SMs and 28 female Explosive Ordnance Disposal (EOD) specialists from the US Air Force, Army, Navy and Marine Corps. RESULTS: Brain Gauge testing revealed significant impairment in performance in SMs with recent concussion. The Al Asad cohort exhibited significantly reduced accuracy (P = .012, Cohen's D 1.0), focus (P = .003, Cohen's D 1.37) and composite Corticalmetric Score (P = .004, Cohen's D 0.96). Readministration of the Brain Gauge several days later revealed improvement in both concussed and control SMs, indicating a practice effect. However, the Al Asad cohort showed greater improvement, likely representing evidence of some degree of recovery from concussion, and narrowing the gap versus controls, though there were still significant differences in focus and Corticalmetric scores. Despite small numbers, the two females with TBI at Al Asad also had significantly worse focus (P < .001, Cohen's D 3.4) and composite Corticalmetric scores (P < .05, Cohen's D 2.7) than female controls on the Brain Gauge. CONCLUSION: Brain Gauge performance is significantly impaired upon initial administration weeks after blast TBI in SMs but shows improvement upon readministration 4-5 days later. Findings in this small sample require replication in larger populations.