Safety Study for Adolescents With Concussion

The purpose of the study was to determine if administration of an exercise stress test
within the first ten days after a sports related concussion would delay or otherwise
interfere with recovery. All participants were adolescents injured while playing sports. All
concussions were confirmed by an experienced sports medicine physician before random
assignment of the participant to receive the treadmill test to determine exercise
intolerance or not.

Recovery was defined as (a) return to asymptomatic state; (b) ability to exercise to
exhaustion without exacerbation of symptoms and (c) confirmation of recovery by a physician
who is blinded to the assignment and to results of exercise testing. Symptoms were self
reported on a daily basis using an online data record.

Regardless of recovery rate all participants were assessed at two weeks following their
first clinic visit. At the second visit all subjects, regardless of group assignment were
assessed on ImPACT, and the treadmill based exercise stress test. Individuals who were not
recovered by the second visit were followed until recovered no matter how long that took.

Analysis of data examined recovery rates of the two groups of adolescents to determine
whether use of a exercise stress test early after concussion caused any adverse events or
interfered in any way with recovery.

Inclusion Criteria:

- Adolescents with sports related concussion that appear for their first clinic visit
within 10 days of injury

Exclusion Criteria:

- Evidence of focal neurologic deficit;

- inability to exercise due to orthopaedic injury;

- diabetes or known heart disease; increased cardiac risk; ADHD; depression; anxiety;
history of moderate or severe brain injury; more than 3 prior concussions;

- inability to understand spoken English.