O3283: Predictive Value of Exercise Step Test after Pediatric and Adolescent Concussion

Background: Previous research has described exercise intolerance on a treadmill test (Buffalo Concussion Treadmill Test) as an important feature of concussion which can serve as a predictor of delayed recovery. The goal of this study was to evaluate the clinical utility of a modified exercise step test to assess exercise tolerance in youth with concussion, and to determine its predictive value for prolonged recovery beyond 28 days.

Methods: Data for this analysis came from a Concussion Registry, which prospectively collects data from the electronic health record (EHR) for patients seen for concussion across a comprehensive regional healthcare network. Patients aged 8-18 years diagnosed with a concussion who were assessed with the exercise step test within 10 days of injury seen between August 2022 and February 2024 were included in the analysis. Prior to starting, patients were fitted with a heart rate monitoring device and instructed to step up onto and down from a 12” box at a metronome pace of 96 bpm for 3-6 minutes. Symptom severity rated on a 0-10 visual analog scale (VAS) and a rating of perceived exertion, were monitored via verbal questioning, and recorded every minute. Criteria for stopping the step test were 1) reaching 85% max age-related HR, 2) increase in VAS of 3 from baseline, 3) 3 or more individual symptoms, 4) inability to perform the examination, or 5) for patient safety. Patient sex, injury mechanism, past medical history, initial symptom burden, and duration in care as a proxy for time to recovery, were abstracted from the EHR. Chi-square testing was used for subgroup analyses.

Results: A total of 264 patients were included. Overall, 103 patients completed the step test without increased symptoms, while 161 patients (61%) met criteria for exercise intolerance (105 completed with increased symptoms; 56 patients were unable to complete the assessment). Step test completion varied by sex, injury mechanism, history of anxiety, history of depression, and teen PCSI score. Patients who did not complete the step test had twice the odds of remaining in care longer than 28 days compared to those completing the step test with no increased symptoms (OR:2.0, CI:1.0-3.9). There was no association between final heart rate achieved during the assessment and length of care.

Conclusion: This study demonstrates the feasibility of identifying exercise tolerance in youth with concussion via a simple in-office step test, with over half of study participants demonstrating exercise intolerance. Further analysis demonstrated that this assessment had strong predictive value in identifying patients with higher risk for prolonged concussion symptoms and recovery. These results have important implications for individualizing rehabilitation strategies since exercise intolerance is a rational therapeutic target via an exercise prescription and can be completed outside of a specialty setting.