Blink duration is increased in concussed youth athletes: a validity study using eye tracking in male youth and adult athletes of selected contact sports.

Objective. Diagnosing a sports-related concussion (SRC) remains challenging, and research into diagnostic tools is limited. This study investigated whether selected eye tracking variables would be a valid tool to diagnose and monitor SRC in adult and youth participants in selected contact sports, such as Rugby Union (rugby) and football (soccer).Methods.This prospective cohort study, with 70 concussed and 92 non-concussed adult and youth athletes, assessed the validity of five previously selected eye tracking variables for SRC diagnostics and management. The performance between concussed and age-matched control (non-concussed) athletes, as well as between three successive testing sessions in the concussed athletes were compared. Self-paced saccade count in adult group; blink duration in the memory-guided saccade and sinusoidal smooth pursuit tasks, proportion of antisaccade errors, and gain of diagonal smooth pursuit in the youth group were assessed.Results.The youth concussed group had higher blink duration in the fast memory-guided saccades task (p = 0.001,η2 = 0.17) and a tendency for higher blink duration in the sinusoidal smooth pursuit task (p = 0.016,η2 = 0.06) compared to the youth control group. In both tasks the blink duration in the concussed youth group decreased from session 1 to session 2 by 24% and 18%, accordingly, although statistical significance was not reached. The concussed adult group demonstrated a lower number of self-paced saccades compared to controls (p = 0.05,η2 = 0.09), which gradually increased, with the largest difference between session 1 and session 3 (p = 0.02).Conclusions. Blink duration in youth athletes holds promise as a valid metric for concussion diagnostics and monitoring. It is recommended to focus future studies on comparing eye tracking performance within the same concussed athletes over time rather than comparing them to healthy controls.

Eye tracking to assess concussions: an intra-rater reliability study with healthy youth and adult athletes of selected contact and collision team sports.

Eye movements that are dependent on cognition hold promise in assessing sports-related concussions but research on reliability of eye tracking measurements in athletic cohorts is very limited. This observational test-retest study aimed to establish whether eye tracking technology is a reliable tool for assessing sports-related concussions in youth and adult athletes partaking in contact and collision team sports. Forty-three youth (15.4 ± 2.2 years) and 27 adult (22.2 ± 2.9 years) Rugby Union and soccer players completed the study. Eye movements were recorded using SMIRED250mobile while participants completed a test battery twice, with a 1-week interval that included self-paced saccade (SPS), fixation stability, memory-guided sequence (MGS), smooth pursuit (SP), and antisaccades (AS) tasks. Intra-class correlation coefficient (ICC), measurement error (SEM) and smallest real difference (SRD) were calculated for 47 variables. Seventeen variables achieved an ICC > 0.50. In the adults, saccade count in SPS had good reliability (ICC = 0.86, SRD = 146.6 saccades). In the youth, the average blink duration in MGS had excellent reliability (ICC = 0.99, SRD = 59.4 ms); directional errors in AS tasks and gain of diagonal SP had good reliability (ICC = 0.78 and 0.77, SRD = 25.3 and 395.1%, respectively). Four metrics were found in this study to be reliable candidates for further biomarker validity research in contact and collision sport cohorts. Many variables failed to present a sufficient level of robustness for a practical diagnostic tool; possibly, because athletic cohorts have higher homogeneity, along with latent adverse effects of undetected concussions and repetitive head impacts. Since reliability of a measure can influence type II error, effect sizes, and confidence intervals, it is strongly advocated to conduct dedicated reliability evaluations prior to any validity studies.

Awareness and Perceived Value of Eye Tracking Technology for Concussion Assessment among Sports Medicine Clinicians: A Multinational Study.

Objective: The awareness of concussion as a serious and frequently occurring sports injury and its management has evolved significantly. One viable objective diagnostic tool is eye tracking technology. The authors hypothesized that while clinicians may be aware that assessing eye movements in concussed athletes can be beneficial, it is possible that, due to the novelty of the eye tracking technology and limited exposure, only a few actually use it in their practice. The study aimed to assess the awareness of eye movement deficits associated with concussion amongst sports medicine clinicians and to determine the utilization and perceptions of the eye tracking technology for concussion diagnosis.Methods: An online 18-question survey was distributed internationally from January until December 2017 and completed by 171 sports medicine clinicians (sport physicians, therapists, general practitioners, neuropsychologists) from 32 countries.Results: Respondents indicated that subjectivity of assessments remained a major limitation of established diagnostic tools. Eye tracking technology, despite its potential to attenuate this limitation, was only used by 12% of respondents. To diagnose concussion, 77% did not use any eye movement assessment tools other than own clinical assessment. With the exception of abnormal pupil light reflex, which was checked by 68%, eye movement deficits were inspected by less than half of the respondents (46.3 ± 12%).Conclusion: Even among sports medicine clinicians who regularly attend to patients with concussions, there is insufficient awareness that concussion can lead to abnormal eye tracking behavior. Lack of exposure to the sensitive eye tracking equipment may be a limiting factor for using eye movement metrics for concussion diagnostics. Facilitating the awareness of objective methods, like eye tracking technology, may help assure the appropriate continuum of identification and treatment for concussed athletes. Increasing educational opportunities and practical experience of clinicians regarding concussive symptoms and potential innovative technology is strongly advocated.