BCAAs in Concussion 2.0

This will be determined by research staff at in person visits by the return to baseline symptom levels along with participant self-report of feeling > 90% back to normal. Percentage recovered at 28 days will be compared between placebo and control group by chi-square testing.

This will be determined by a comparison of total score on the Post-concussion Symptom Scale (PCSS) (22 symptoms each rated on a 0-6 Likert scale, total scale of 0-132). A participant is deemed recovered when total score is within 3 points of their pre-injury score, time to recovery will be compared among placebo and control groups by Wilcoxon rank sum test.

This will be determined by the visio-vestibular examination (VVE) score, a score of 0-9 based on accumulation of abnormalities on the nine elements of the VVE. Average VVE score will be compared among placebo and control groups by Wilcoxon rank sum tests.

This will be determined by a comparison of the average maximum pupil diameter (measured in mm, scale 0-9 mm) between placebo and control using Wilcoxon rank sum test, whereby larger pupil diameter represents an abnormality.

This will be determined by a comparison of the average minimum pupil diameter (measured in mm, scale 0-9 mm) between placebo and control using Wilcoxon rank sum test, whereby larger pupil diameter represents an abnormality.

This will be determined by a comparison of the average percentage of pupil constriction change (measured in %, scale 0-100) between placebo and control using Wilcoxon rank sum test, whereby larger percent represents an abnormality.

This will be determined by a comparison of the average constriction latency (measured in ms, scale 0-1000 ms) between placebo and control using Wilcoxon rank sum test, whereby shorter latency represents an abnormality.

This will be determined by a comparison of the median average constriction velocity (measured in mm/s, scale 0-5 mm/s) between placebo and control using Wilcoxon rank sum test, whereby faster constriction velocity represents an abnormality.

This will be determined by a comparison of the average peak constriction velocity (measured in mm/s, scale 0-5 mm/s) between placebo and control using Wilcoxon rank sum test, whereby faster constriction velocity represents an abnormality.

This will be determined by a comparison of the median average dilation velocity (measured in mm/s, scale 0-5 mm/s) between placebo and control using Wilcoxon rank sum test, whereby faster dilation velocity represents an abnormality.

This will be determined by a comparison of the average peak dilation velocity (measured in mm/s, scale 0-5 mm/s) between placebo and control using Wilcoxon rank sum test, whereby faster velocity represents an abnormality.

This will be determined by a comparison of the average time to reach 75% of the original baseline pupil diameter (T75) after peak constriction (measured in s, scale 0-4 s) between placebo and control using Wilcoxon rank sum test, whereby faster time represents an abnormality.

Sleep quality will be determined by utilization of the PROMIS sleep questionnaire with 8 questions and a 5 point scale (1- not at all, 2- a little bit, 3- somewhat, 4- quite a bit and 5- very much). The PROMIS Sleep Disturbance score is calculated by adding up the raw scores for each item on the PROMIS Sleep Disturbance scale. The score is then rescaled to a standardized T-score using a conversion table. A higher score indicates greater sleep disturbance. Total range of score is 8-40. Average score will be compared between placebo and control using Wilcoxon rank sum test.

Physical activity will be determined by utilization of the PROMIS sleep questionnaire with 8 questions and an aggregate score of X. Physical activity will be determined by utilization of the PROMIS Physical Activity questionnaire with 8 questions and a 5 point scale (1- not at all, 2- a little bit, 3- somewhat, 4- quite a bit and 5- very much). A higher aggregate score may be indicative of greater activity limitations or reduced activity levels. Total range of score is 8-40. Average score will be compared between placebo and control using Wilcoxon rank sum test.