Date of this Version
The topic of mild traumatic brain injury (mTBI) has rapidly gained attention not only in academic science but also in popular media. Unlike severe traumatic brain injury, mTBI is difficult to diagnose. There are no objective diagnostic criteria, and symptoms can vary greatly across individuals. Further, although individuals with mTBI are frequently compared to non-injured individuals, it cannot be concluded with certainty that any differences found between groups can be attributed solely to the head injury and not a more general injury-factor. Identifying a sensitive and specific physiological signal across similar injury groups is critical to establishing a criterion that would facilitate the development of tools which could be rapidly employed. The purpose of the present study was to investigate neurophysiological functioning in individuals who recently sustained a mTBI or orthopedic injury, as well as non-injured individuals, using multiple electrophysiological analysis procedures.
Twenty-four participants ages 18-30 were recruited for this study. Individuals were in one of three groups: mTBI (3 males and 3 females; age M: 22.50), mild orthopedic injury (6 males and 2 females; age M:20.76), or non-injured (2 males and 8 females; age M: 21.50). Injured participants took part in the study no longer than ten days post-injury. All participants completed a resting state task, analyzed with quantitative EEG, and two cognitive event-related potential (ERP) tasks: auditory oddball and n-back.
Results indicated no significant group differences for resting state or n-back. However, the mTBI group displayed significantly larger P300 amplitudes during the auditory oddball. Although some individuals with mTBI may show reduced activation in brain areas supporting working memory, areas outside this network are recruited and included in order to meet task demands, which could account for the increase in amplitude. The current study lends support for the use of ERP, specifically with an auditory oddball task, in the identification of acute mTBI. Of primary significance is the inclusion of an orthopedic injury group and the finding that P300 amplitude is significantly increased only for those with mTBI. This provides an important basis for future research and strategies for the development of a rapid, objective measure of mTBI.
Advisors: Arthur C. Maerlender and Cary Savage