Abstract:
Context: Recent research has focused on the role that computerized cognitive testing plays in the diagnosis, treatment, and decisions related to returning to physical activity following concussion 1–3. However, little investigation has been done testing the attentional deficits of high school aged athletes recovery. Objective: The purpose of this study is to identify differences in tracking recovery for two months after concussion with three assessments which examine different levels of cognitive function. As sport-related concussion research in the adolescent population is limited 4, this study seeks to enhance our understanding of the effect of concussion on different components of attentional function and examine their respective recovery curves. Such information would allow us to identify measures of cognitive function which sensitively reflect functional recovery and provide clinicians objective evidence to optimize timing of return to normal activity decisions. Design: Cohort study. Setting: Within a visually enclosed space in a laboratory, cognitive disturbances after concussion were assessed using three different computerized tests: ImPACT, Attentional Network Test (ANT), and Task Switching Test (TS). Patients: High school athletes who suffered a concussion in the Eugene area were identified by a certified Athletic Trainer. Each of the concussion subjects (n=12) were matched with a healthy control (n=12) and underwent examination in the following time increments: within 72 hours, one week, two weeks, one month, and two months post injury. Main Outcome Measures: Dependent variables were the ImPACT composite scores, the alerting, orienting, and conflict effects derived from the ANT, and the switch cost calculated from the TS. A two-way, mixed effects ANOVA was performed to determine differences between groups across time. Results: Concussion subjects performed significantly worse on the visual memory composite of ImPACT (mean difference=17.1; SError=4.73; P= .002) and the switch cost component of the TS (mean difference=21.77; SError =6.79; P=.004) within 72 hours of injury. Symptom score group differences were present up to one week after injury (mean difference =26.98; SError=6.93; P= .001). Conclusions: This investigation elucidates the inability of concussed high school athletes to effectively switch their attention between tasks initially after concussion. While symptom monitoring continues to be a tool to detect deficits, other objective measures are needed to detect subtle cognitive changes following concussion over an extended period of time post-injury. The switch cost and visual memory group differences demonstrate two measures which detect disturbances after concussion in high school athletes. Attentional testing revealed similar differences as ImPACT, but through an individualized analysis, certain subjects showed prolonged signs of impairment following concussion indicating long term deficits when analyzed on an individual basis. Therefore, the TS may prove to be an easily administered and useful clinical test sensitive to the disturbances seen after concussion in the adolescent population.