An Examination of Adolescent Athletes and Nonathletes on Baseline Neuropsychological Test Scores.

CONTEXT: An estimated 15.3 million adolescent students are enrolled in US high schools, with approximately 7.8 million participating in athletics. Researchers have examined various demographics in high school athletes; however, athletic participation may play a larger role in test performance than previously thought. Currently, investigations of concussion assessment may rely on uninjured athletes as controls. However, due to the intense nature of athletics, this may not be an appropriate practice. OBJECTIVE: To examine differences between athletes and nonathletes using a common computerized neuropsychological test. DESIGN: Retrospective cross-sectional study. SETTING: High schools from a school district in Columbus, Ohio. PATIENTS OR OTHER PARTICIPANTS: A total of 662 adolescent high school students (athletes: n = 383, female n = 18; nonathletes: n = 279, female n = 193). MAIN OUTCOME MEASURE(S): Participants were administered a computerized neuropsychological test battery (Immediate Post-Concussion Assessment and Cognitive Test [ImPACT]) during baseline concussion assessment. Differences between groups were established for output composite scores. RESULTS: Differences were found between athletes and nonathletes in composite reaction time ( F1,522 = 14.855, P < .001) and total symptom score ( F1,427 = 33.770, P < .001). Nonathletes reported more symptoms, whereas athletes had faster reaction times. No differences were present in composite verbal memory, composite visual memory, composite visual motor speed, or composite impulse control ( P > .05). CONCLUSIONS: Symptom reporting and reaction time differed between high school athletes and nonathletes. Participation in extracurricular activities may lead to cognitive differences in adolescents that can influence performance on the Immediate Post-Concussion Assessment and Cognitive Test battery. Researchers should account for these differences in baseline performance when making concussion diagnostic and management decisions.

The Role of Gender in Neuropsychological Assessment in Healthy Adolescents.

CONTEXT: Research in college athletes has revealed significant gender differences in areas of verbal memory, visual memory, and reaction time. Additionally, research has focused on differences in neuropsychological components and gender in college populations; however, such differences in gender have not been documented in healthy adolescent populations. PURPOSE: To identify potential differences between males and females using different components of a common computerized neuropsychological test. METHODS: A computerized neuropsychological test battery (ImPACT®) was administered to 662 high-school age adolescent athletes (male: n = 451 female: n = 262). Differences between genders were calculated using a 1-way ANOVA. All statistical analyses were conducted using SPSS 23.0. Significance levels were set a priori at P < .05. RESULTS: A 1-way ANOVA revealed statistically significant differences between males and females for composite reaction time (F1,660 = 10.68, P = .001) and total symptom score (F1,660 = 81.20, P < .001). However, no statistically significant differences were found between males and females in composite verbal memory, visual memory, visual motor, or impulse control (P > .05). CONCLUSIONS: Significant differences between males and females were discovered for composite reaction time and total symptom scores, with females reporting more symptoms and slower reaction times at a baseline assessment. Increased symptom reporting by females may be attributed to both hormonal differences and increased honesty. Quicker reaction times in males may support theories that repetition of activities and quicker muscle contraction are gender dependent. However, additional research is necessary to understand gender differences in adolescent athletes during periods of cognitive and physical maturation.

Repetitive head impacts do not affect postural control following a competitive athletic season.

Evidence suggests that Repetitive Head Impacts (RHI) directly influence the brain over the course of a single contact collision season yet do not significantly impact a player's performance on the standard clinical concussion assessment battery. The purpose of this study was to investigate changes in static postural control after a season of RHI in Division I football athletes using more sensitive measures of postural control as compared to a non-head contact sports. Fourteen Division I football players (CON) (age=20.4±1.12years) and fourteen non-contact athletes (NON) (2 male, 11 female; age=19.85±1.21years) completed a single trial of two minutes of eyes open quiet upright stance on a force platform (1000Hz) prior to athletic participation (PRE) and at the end of the athletic season (POST). All CON athletes wore helmets outfitted with Head Impact Telemetry (HIT) sensors and total number of RHI and linear accelerations forces of each RHI were recorded. Center of pressure root mean square (RMS), peak excursion velocity (PEV), and sample entropy (SampEn) in the anteroposterior (AP) and mediolateral (ML) directions were calculated. CON group experienced 649.5±496.8 mean number of impacts, 27.1±3.0 mean linear accelerations, with ≈1% of total player impacts exceeded 98g over the course of the season. There were no significant interactions for group x time RMS in the AP (p=0.434) and ML (p=0.114) directions, PEV in the AP (p=0.262) and ML (p=0.977) directions, and SampEn in the AP (p=0.499) and ML (p=0.984) directions. In addition, no significant interactions for group were observed for RMS in the AP (p=0.105) and ML (p=0.272) directions, PEV in the AP (p=0.081) and ML (p=0.143) directions, and SampEn in the AP (p=0.583) and ML (p=0.129) directions. These results suggest that over the course of a single competitive season, RHI do not negatively impact postural control even when measured with sensitive non-linear metrics.

ASB clinical biomechanics award winner 2016: Assessment of gaze stability within 24-48hours post-concussion.

BACKGROUND: Approximately 90% of athletes with concussion experience a certain degree of visual system dysfunction immediately post-concussion. Of these abnormalities, gaze stability deficits are denoted as among the most common. Little research quantitatively explores these variables post-concussion. As such, the purpose of this study was to investigate and compare gaze stability between a control group of healthy non-injured athletes and a group of athletes with concussions 24-48hours post-injury. METHODS: Ten collegiate NCAA Division I athletes with concussions and ten healthy control collegiate athletes completed two trials of a sport-like antisaccade postural control task, the Wii Fit Soccer Heading Game. During play all participants were instructed to minimize gaze deviations away from a central fixed area. Athletes with concussions were assessed within 24-48 post-concussion while healthy control data were collected during pre-season athletic screening. Raw ocular point of gaze coordinates were tracked with a monocular eye tracking device (240Hz) and motion capture during the postural task to determine the instantaneous gaze coordinates. This data was exported and analyzed using a custom algorithm. Independent t-tests analyzed gaze resultant distance, prosaccade errors, mean vertical velocity, and mean horizontal velocity. FINDINGS: Athletes with concussions had significantly greater gaze resultant distance (p=0.006), prosaccade errors (p<0.001), and horizontal velocity (p=0.029) when compared to healthy controls. INTERPRETATION: These data suggest that athletes with concussions had less control of gaze during play of the Wii Fit Soccer Heading Game. This could indicate a gaze stability deficit via potentially reduced cortical inhibition that is present within 24-48hours post-concussion.