Statement of purpose Visual and autonomic system disturbances are common sequelae of concussion. Clinical concussion diagnosis currently relies on subjective assessments such as symptom questions such as the Post-Concussion Symptom Inventory (PCSI). Quantification of visual and autonomic dysfunction could provide an objective method of acute diagnosis and subacute identification of ongoing injury.
Methods/Approach We collected objective eye tracking data from three cohorts ages 12–17 years: healthy controls (n=105, mean age: 15.3, 56.2% female), concussed cases seen within 28 days of injury (acute, n=125, mean days since injury:12.5, mean age: 15.4, 46.4% female) and concussed cases seen within 29–90 days of injury (sub-acute, n=94, mean days since injury: 53.6, mean age: 15.4, 70.2% female). We compared self-reported symptoms and eye tracking metrics across groups using a series of chi-square analyses and one-way analysis of variance, with Tukey’s range test for post-hoc testing. Bonferroni corrections were used to account for multiple comparisons.
Results Controls reported significantly lower PCSI scores (mean ± SD: 6.0 ± 9.1) than acute cases (31.2 ± 24.7, p < 0.001) and sub-acute cases (31.4 ± 27.8, p < 0.001). A significantly lower proportion of controls experienced symptoms after completing the assessment (10%) than acute cases (55%, p < 0.001) and sub-acute cases (38%, p < 0.001). Six eye tracking metrics related to pupil diameter (left and right pupil size mean and median values, mean and median differences in left and right pupil size), were significantly greater among acute and sub-acute cases compared to controls.
Conclusion Measures of pupil diameter were greater for acute and sub-acute cases compared to healthy controls, suggesting autonomic dysfunction post-injury. No other metrics related to eye movement were discriminatory in this cohort, likely due to the heterogeneity of concussion.
Significance These findings support the quantification of visual and autonomic dysfunction as objective markers of pediatric concussion.