The Effect Of Concussion History On The Vestibular System And Postural Stability In Reserve Officers' Training Corps Cadets

PURPOSE: A newer trend in concussion diagnostics and therapeutics is the classification of concussion phenotypes, theorized to play an important role in treatment and management. Research has not yet examined long-term concussive effects within different subtyping categories. The purpose of this study was to describe the relationship between a history of concussion, postural stability, and vestibular function in Reserve Officers’ Training Corps (ROTC) Cadets. METHODS: One hundred and twenty Cadets (female n = 26) from a Senior Military College in the Southeast U.S. were voluntarily enrolled. Participants completed a history of concussion questionnaire (concussion n = 45, no concussion n = 75). Cadets utilized a cell phone application to measure stability (range = 0-100) during a series of balance tasks (3 rounds, 10 seconds each): feet together (FT), single leg right (SLR) and left (SLL), tandem right (TR) and left (TL). A subsample (n = 36) completed the Vestibular Ocular Motor Screening (VOMS) protocol. Independent sample t-tests were applied to assess balance task differences between concussion history groups. A Mann-Whitney analysis was completed to examine participant-reported symptoms during the VOMS protocol. RESULTS: Participants with a history of concussion had a higher score, indicating better balance, in all balance tasks (total score: concussion: 90.68 ± 6.98, no concussion: 87.12 ± 11.7, p = 0.013). The TR task had the largest difference between groups (concussion: 96.15 ± 5.13, no concussion: 90.52 ± 13.64, p = .001). VOMS distribution of scores were similar across concussion history; however, the concussion group had a higher mean rank (concussion = 20.42, no concussion = 16.58). VOMS convergence distance (cm) was not different between groups (concussion: 2.59 ± 2.19, no concussion: 3.04 ± 2.83, p = .670). CONCLUSIONS: Surprisingly, participants with a history of concussion demonstrated better postural stability as measured by balance tasks compared to participants without a history of concussion. These data represent important initial steps to providing an understanding of the history of concussions that may be beneficial to the long-term care of military populations.