This paper is a revision and update of the recommendations developed following the 1st (Vienna) and 2nd (Prague) International Symposia on Concussion in Sport.1,2 The Zurich Consensus statement is designed to build on the principles outlined in the original Vienna and Prague documents and to develop further conceptual understanding of this problem using a formal consensus-based approach. A detailed description of the consensus process is outlined at the end of this document under the background section (see Section 11). This document is developed for use by physicians, therapists, certified athletic trainers, health professionals, coaches, and other people involved in the care of injured athletes, whether at the recreational, elite, or professional level.
While agreement exists pertaining to principal messages conveyed within this document, the authors acknowledge that the science of concussion is evolving and, therefore, management and return-to-play (RTP) decisions remain in the realm of clinical judgment on an individualized basis. Readers are encouraged to copy and distribute freely the Zurich Consensus document and the Sports Concussion Assessment Tool (SCAT2) card, and neither is subject to any copyright restriction. The authors request, however, that the document and the SCAT2 card be distributed in their full and complete format.
The following focus questions formed the foundation for the Zurich concussion consensus statement:
Acute Simple Concussion
- Which symptom scale and which sideline assessment tool is best for diagnosis and/or follow-up?
- How extensive should the cognitive assessment be in elite athletes?
- How extensive should clinical and neuropsychological (NP) testing be at non-elite level?
- Who should do/interpret the cognitive assessment?
- Is there a sex difference in concussion incidence and outcomes?
- Is provocative exercise testing useful in guiding RTP?
- What is the best RTP strategy for elite athletes?
- What is the best RTP strategy for non-elite athletes?
- Is protective equipment (eg, mouthguards and helmets) useful in reducing concussion incidence and/or severity?
Complex Concussion and Long-Term Issues
- Is the simple versus complex classification a valid and useful differentiation?
- Are there specific patient populations at risk of long-term problems?
- Is there a role for additional tests (eg, structural and/or functional magnetic resonance [MR] imaging, balance testing, biomarkers)?
- Should athletes with persistent symptoms be screened for depression/anxiety?
- Which symptom scale is appropriate for this age group?
- Which tests are useful, and how often should baseline testing be performed in this age group?
- What are the most appropriate RTP guidelines for elite and non-elite child and adolescent athletes?
- What is the best method of knowledge transfer and education?
- Is there evidence that new and novel injury prevention strategies work (eg, changes to rules of the game, fair play strategies, etc)?
The Zurich document additionally examines the management issues raised in the previous Prague and Vienna documents and applies the consensus questions to these areas.