Blog: Announcement: To CT, or not to CT? Clinical Decision Rules for Concussion

Blog: Announcement: To CT, or not to CT? Clinical Decision Rules for Concussion 

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Posted on May 08, 2015
Tags:  (Concussion)  (Head Injury) 
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May 11, 2015 - This week's post is also available from the Cochrane Child Health blog.

Head trauma. Headache. Nausea. Loss of balance. Dizziness. Difficulty concentrating. Confusion. Behavioural changes. Sleep changes.

It might be a concussion. What next?

With growing attention in research and the media, it is becoming clear that concussions are very serious injuries with sometimes lasting effects. As an emergency physician, the chances are good that you have treated many children with these symptoms – pediatric concussion is considered a silent epidemic [1]. In the US, estimates suggest up to 3.8 million concussions occur every year, resulting in over 700,000 Emergency Department visits [2]. Because of this, head trauma is one of the most common reasons for consultation in the Emergency Department [3]. 

Concussion symptoms typically alleviate within 72 hours, and completely resolve in 7 to 10 days [4]. However, in many cases, children and youth experience ongoing or recurrent headache, behavioural changes, and other physical symptoms, requiring subsequent Emergency Department and primary care physician visits [4]. It was estimated in one Canadian study that 58% of children with concussion remained symptomatic in the first month, 11% at 3 months, and 2% beyond one year [5]. These findings reinforce that concussions are serious injuries that can last over time. 

Considering the significant morbidity of concussion, and its impact on quality of life and school participation, identifying kids at risk for long-term consequences and those in need of neurosurgical intervention is crucial. There is an increasing tendency by physicians to perform early diagnostic imaging through CT scan for suspected concussion because it is linked to better outcomes, lower admission rates, and serves as the diagnostic standard for identifying intracranial injury [6]. However, it isn’t feasible or necessary to conduct this scan with all children presenting with concussion symptoms. This makes a clinical decision rule for CT scans important. With summer around the corner, and team sports ramping up for the season, understanding and using effective and validated clinical decision rules is essential to identify children at risk for intracranial injury. 

When to CT: The evidence

In a recent systematic review, Pickering et al. reviewed evidence from 16 RCTs (representing 14 cohorts and 79,740 patients) to determine which clinical decision tool is most accurate at predicting which pediatric patients will have an intracranial injury on CT or require neurosurgical intervention [6]. Sensitivity and specificity were determined for 11 decision rules: 

  • UCD Rule
  • Chalice Rule
  • PECARN (≥2yrs <18yrs, and <2 yrs)
  • Buchanich 2007 Rule
  • Dietrich 1993 Rule
  • Greenes 1999 Rule
  • Greenes 2001 Scoring System
  • Atabaki 2008 Rule
  • CATCH Rule
  • New Orleans Criteria

Which rule? 

Of the 11 clinical decision rules published at the time of the review (2011), methodologically, PECARN was identified as the strongest rule with the greatest validity, largest study cohort, highest sensitivity and acceptable specificity for clinically significant intracranial injury.

PECARN is the recommended clinical decision rule for identifying children at risk for intracranial injury who require imaging in Canada [1]. However, in the UK, because the CHALICE-derived National Institute for Health and Clinical Excellence (NICE) criteria for CT scan forms the basis for 85% of management decisions in the Emergency Department [6], the authors acknowledged its continued use as an acceptable and cost-effective alternative more in keeping with National Health Service-based practice. 

The PECARN Management Algorithm for Children after Head Trauma was initially published in the Lancet in 2009, and was based on a derivation and validation study involving 42,412 children [7]. The algorithm has separate considerations for children younger than 2 years and 2 years or older. It is available through trekk.ca or directly on the Ontario Neurotrauma Foundation website on page 53 of their Guidelines for Diagnosing and Managing Pediatric Concussion [8].

The authors concluded that the PECARN algorithm provides "highly accurate prediction rules for children at very low risk of clinically-important traumatic brain injuries for whom CT scans should be avoided. Application of these rules could limit CT use, protecting children from unnecessary radiation risks” [7].


The heterogeneity of the rules included in the review prevented any meta-analysis of the data. The authors noted that a shift in practice from identification of any lesion on a CT scan to focusing on clinically significant lesions has made results of studies difficult to compare. The authors suggested: “future research efforts in this field should concentrate on the universal application of definitions for patient populations, inclusion criteria, reference standards, and outcome criteria” [7].


TRanslating Emergency Knowledge for Kids (TREKK):

Concussion Bottom Line Recommendations

Recommendations de Base: Commotion Cérébrale

Concussion Evidence Repository

Emergency Medicine Cases Podcast: Pediatric head injury


1. TREKK Bottom Line Recommendations: Concussion (English Version)

2. McCrory, P., Meeuwisse, W., Aubry, M., Cantu, B., Dvorak, J., Echemendia, R., . . . Turner, M. (2013). Consensus statement on Concussion in Sport - The 4th International Conference on Concussion in Sport held in Zurich, November 2012. Phys Ther Sport, 14(2), e1-e13. doi: 10.1016/j.ptsp.2013.03.002

3. Farrell, C. A. (2013). Management of the paediatric patient with acute head trauma. Paediatrics and Child Health (Canada), 18(5), 253-258.

4. Scorza, K. A., Raleigh, M. F., & O'Connor, F. G. (2012). Current concepts in concussion: Evaluation and management. American Family Physician, 85(2), 124-132.

5. Barlow, K. M., Crawford, S., Stevenson, A., Sandhu, S. S., Belanger, F., & Dewey, D. (2010). Epidemiology of postconcussion syndrome in pediatric mild traumatic brain injury. Pediatrics, 126(2), e374-381. doi: 10.1542/peds.2009-0925

6. Pickering, A., Harnan, S., Fitzgerald, P., Pandor, A., & Goodacre, S. (2011). Clinical decision rules for children with minor head injury: A systematic review. Archives of Disease in Childhood, 96(5), 414-421. doi: 10.1136/adc.2010.202820

7. Kuppermann, N., Holmes, J. F., Dayan, P. S., Hoyle, J. D., Jr., Atabaki, S. M., Holubkov, R., . . . Wootton-Gorges, S. L. (2009). Identification of children at very low risk of clinically-important brain injuries after head trauma: a prospective cohort study. Lancet, 374(9696), 1160-1170. doi: 10.1016/s0140-6736(09)61558-0

8. Zemek, R., Duval, S., Dematteo, C. et al. (2014). Guidelines for Diagnosing and Managing Pediatric Concussion. Toronto, ON: Ontario Neurotrauma Foundation