Graded Exercise Testing Predicts Recovery Trajectory of Concussion in Children and Adolescents

Orr R, Bogg T, Fyffe A, Lam LT, Browne GJ. Clin J Sport Med. 2018 [Epub ahead of print]

Take Home Message: Graded exercise testing with clinical provocative tests in the subacute phase after a concussion can help clinicians predict time to recovery and guide decision making for readiness to start return to activity.

Medical professionals are often conservative when returning a pediatric athlete to activity after a concussion to protect an immature brain. However, patients who exercise in the subacute phase may improve a clinician’s ability to quantify a patient’s symptoms and improve outcomes post-concussion. Therefore, the authors performed a graded exercise treadmill test on 139 athletes (~12 years old; 73% boys) 5 to 7 days post injury to investigate whether graded exercise testing could predict recovery. Each athlete completed the graded exercise program according to the Bruce treadmill test protocol. During testing, an athlete’s speed and running incline was increased every 3 minutes until they ended the test. The authors used 4 criteria to end testing:

  1. participant asked to stop
  2. significant gait impairment, loss of balance, or coordination
  3. abnormal heart rate response
  4. reported symptoms increase by >3 points (out of a 7-point Likert scale)

The researchers measured exercise time to symptom exacerbation and placed participants into two groups: exercise tolerant (76 participants) or exercise intolerant (64 participants). Exercise tolerance for readiness to return to activity was defined as the ability to exercise without worsening symptoms for at least 9 minutes. The authors noted that neither group had no adverse effects from exercise. The authors then assessed participants every 2 weeks and noted recovery. Within this study, the authors defined clinical concussion recovery as the clinical scores (post-concussion symptom checklist, vestibular-ocular-motor screen, modified BESS, and ImPACT) returning to baseline norm. The exercise tolerant participants exercised for ~10 minutes compared to only ~4 minutes among the exercise intolerant participants. The exercise tolerant group recovered within 10 days. However, the exercise intolerant participants took ~45 days to recover. Lastly, the authors found that participants who were exercise intolerant and had a positive modified BESS (score of 1) were 3 times more likely to have prolonged recoveries (recover > 14 days; 93% accuracy, 89% specificity, 82% sensitivity).

The authors of this study showed a treadmill test can help stratify young athletes based on risk of prolonged recovery. Specifically, when athletes in the subacute phase of healing (~5 to 7 days post injury) withstood more than 9 minutes of running without an increase in signs and symptoms they were more likely to recovery in ~10 days. This is a stark contrast to the athletes that were unable to withstand 9 minutes on the treadmill and took ~45 days to recover. It is also interesting to note that when the treadmill test is added to the modified BESS there is an even greater predictive value. The authors demonstrated that the treadmill test and modified BESS test was 93% predictive; however, it will be helpful to confirm this in other studies/clinics. These tests may help clinicians overcome the challenges of directing patient care after a concussion and help them explain to patients the possible timeline for recovery.

Questions for Discussion: Would you consider implementing the treadmill test? Do you think adding this test could also help with directing patient care during recovery?

Written by: Jane McDevitt

Reviewed by: Jeffrey Driban

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Delayed Onset of Concussion Symptoms may Predict Delayed Recovery in Young Athletes Predicting the Persistence of Concussion-Related Impairments

Concussions: Sex Difference in Symptoms & Long-Term Balance Issues