ABSTRACT
Mild traumatic brain injury (mTBI) remains a diagnostic challenge and therefore strategies for objective assessment of neurological function are key to limiting long-term sequelae. Current assessment methods are not optimal in austere environments such as athletic fields; therefore, we developed an immersive tool, the Display Enhanced Testing for Cognitive Impairment and mTBI (DETECT) platform, for rapid objective neuropsychological (NP) testing. The objectives of this study were to assess the ability of DETECT to accurately identify neurocognitive deficits associated with concussion and evaluate the relationship between neurocognitive measures and subconcussive head impacts. DETECT was used over a single season of two high school and two college football teams. Study participants were instrumented with Riddell Head Impact Telemetry (HIT) sensors and a subset tested with DETECT immediately after confirmed impacts for different combinations of linear and rotational acceleration. A total of 123 athletes were enrolled and completed baseline testing. Twenty-one players were pulled from play for suspected concussion and tested with DETECT. DETECT was 86.7% sensitive (95% confidence interval [CI]: 59.5%, 98.3%) and 66.7% specific (95% CI: 22.3%, 95.7%) in correctly identifying athletes with concussions (15 of 21). Weak but significant correlations were found between complex choice response time (processing speed and divided attention) and both linear (Spearman rank correlation coefficient 0.262, p = 0.02) and rotational (Spearman coefficient 0.254, p = 0.03) acceleration on a subset of 76 players (113 DETECT tests) with no concussion symptoms. This study demonstrates that DETECT confers moderate to high sensitivity in identifying acute cognitive impairment and suggests that football impacts that do not result in concussion may negatively affect cognitive performance immediately following an impact. Specificity, however, was not optimal and points to the need for additional studies across multiple neurological domains. Given the need for more objective concussion screening in triage situations, DETECT may provide a solution for mTBI assessment.
ABSTRACT
INTRODUCTION: Despite many existing treatments, airsickness is an issue of concern for soldiers being transported by helicopter. This experiment examined the efficacy of four airsickness treatments and their effects on performance. This study replicated the transport of soldiers in the cabin of an UH-60 Black Hawk helicopter performing many of the flight maneuvers potentially experienced in a night troop transport during turbulent conditions. METHODS: A double-blinded, placebo-controlled design was used to compare the effectiveness of four airsickness countermeasures to their placebo controls. There were 64 male, non-aviator subjects (ages 18-34 yr) who were recruited for the study. Of these, 16 subjects were randomly assigned to each of 4 groups: (1) promethazine (25 mg) + caffeine (200 mg); (2) meclizine (25 mg); (3) Scopolamine patch (1.5 mg); and 4) acustimulation wristband. Each individual participated twice, once with the treatment and once with placebo. RESULTS: The findings indicated that only the combination of promethazine + caffeine showed a statistically significant reduction in nausea and motion sickness severity, and an improvement in reaction time when compared with its placebo control. DISCUSSION: Data from this study indicated that of the countermeasures tested, promethazine + caffeine was the most effective at reducing airsickness while producing the fewest side effects when compared with its placebo. In addition, this study demonstrated that over-the-counter caffeine can serve as an effective stimulant counterpart to promethazine. This may be a more appealing option than employing scheduled sympathomimetic drugs in a combat environment.
