Zurich 2012: Concussion Consensus Statement Update

By: March 14, 2013

Every 3 or 4 years concussion experts from around the world gather to update all stakeholders (health care providers, coaches, parents and organizations) on the evidence to date for concussions in sport. The resulting document that emerges from these brilliant minds is then worshipped as the holy grail of concussion information for the next several years. This is the 4th consensus statement released since the inaugural Vienna conference in 2001. To read the full consensus statement published in April’s edition of BJSM click here.

To avoid redundancy from the consensus statement summary itself, in this blog I will focus on the notable updates and changes to the document since the last consensus statement from Zurich 2008. Those familiar with the Zurich 2008 consensus statement will notice that there are minimal number of controversial changes this time around (unlike previous consensus statements). However the issues that stood out worthy of mention were preseason neuropsychological testing (ie. ImPACT), concussion management, Chronic Traumatic Encephalopathy (CTE), protective equipment and the transition to the SCAT3.

Neuropsychological testing (ie. ImPACT)-slow down folks
Computerized baseline neuropsychological tests have become a huge (fear based media driven?) issue in recent years. For years professional sports have added computerized baseline tests to their preseason testing, but now local youth organizations such as the GTHL and Oakville Minor hockey (among a growing number of other organizations) are paying approximately $25 per player for widespread baseline testing. Parents are largely supportive as they believe their kids are getting the same concussion management protocol as the pros. But hot off the press from the experts: “at present, there is insufficient evidence to recommend the widespread routine use of baseline neuropsychological testing”. It is true that lack of evidence is not evidence for lack of efficacy. And I am not saying those organizations that choose to pay for these tests are foolish, in fact we have implemented ImPACT testing with the Milton Icehawks Jr.A hockey team for the last 2 years. However, it is important to note this testing is being fuelled by interest groups and media reports, NOT world leading experts. In my experience using ImPACT testing with concussed junior hockey players, it is a valuable tool however it rarely is necessary to make an informed return to play decision for a player.

Concussion management- is rest good enough?
The cornerstone of concussion management historically has been physical and cognitive rest until the symptoms resolve and then a graded programme of exertion prior to medical clearance and RTP. The gradual return to play protocol has been recommended since the original consensus statement over a decade ago, and few professionals would argue with this approach. The majority (80–90%) of concussions resolve in a short (7–10 day) period. So rest followed by a graded programme of exertion is practical for these athletes. But what about the 10-20% of concussed athletes still experiencing post concussive symptoms after 10 days? Although continued rest seems reasonable, does it lead to optimal/rapid recovery? Unfortunately there is simply lack of evidence supporting any specific management recommendations (including physical and cognitive rest). Zurich 2008 consensus statement said “apart from limiting physical and cognitive activities no further intervention is required during recovery”. The current consensus statement is the first to say that “low-level exercise for those who are slow to recover may be of benefit”. This is a colossal, optimistic change (in my opinion) as it opens the door for research on active rehabilitation management protocols. I am unsure why the work of JJ Leddy from the University of Buffalo on sub-symptom threshold aerobic exercise to treat post concussive symptoms has yet to be referenced or discussed in these consensus statements. Also of interest would be testing the vestibular rehabilitation protocols, such as those used by Dr. Carrick (Chiropractic neurologist famous for treating Sydney Crosby and many other pro athletes struggling with returning to play after a concussion).

Chronic Traumatic Encephalopathy (CTE)- proceed with caution
Unless you have been living under a rock you have probably heard or read about the Boston University Brain Bank. The Centre for the Study of Traumatic Encephalopathy has been publishing case reports on the pathological findings from donated brains of several NFL and NHL players. CTE is a neurodegenerative disease linked to dementia, memory loss and depression. According to researchers the disease is triggered by repeated head trauma and can be confirmed only by examining the brain after death. Although these case studies and case series make for well circulated media reports, they are the bottom of the research credibility totum pole. The current consensus statement makes specific reminder that a cause and effect relationship has yet to be determined between CTE and concussions or exposure to sports. In a review by McCrory also published in April, 2013’s edition of BJSM it is noted that the extent to which age-related changes, psychiatric or mental health illness, alcohol/drug use or coexisting dementing illnesses contribute to the process of CTE is largely unaccounted for in the published literature. Although we must proceed with caution interpreting the findings from these case reports, prepare for much more to come on this topic as researchers may have made a significant breakthrough….

Helmet’s and mouthguard’s- it’s not about the equipment
Straight from the consensus statement: “There is no good clinical evidence that currently available protective equipment will prevent concussion, although mouthguards have a definite role in preventing dental and orofacial injury. Biomechanical studies have shown a reduction in impact forces to the brain with the use of head gear and helmets, but these findings have not been translated to show a reduction in concussion incidence.”

This has not changed from the Zurich 2008 consensus statement, however deserves some attention due to the ongoing search and emphasis manufacturers place on creating the best concussion prevention helmet. The message here is stop relying on equipment to prevent concussion and shift the emphasis to rule changes to make each sport safer. Education and awareness campaigns such as Dr. Charles Tator’s ThinkFirst are key prevention initiatives deserving of more attention. Disclaimer: helmet’s and mouthgaurds do protect against other head and facial injuries (so don’t go 70’s NHL with your kids), but concussions are a complex multifactorial beast.

SCAT3-Sport Concussion Assessment Tool 3rd Edition
These changes are probably only of interest to health care providers and field therapists.

For those who have been using the SCAT2 it is important to note there is no evidence to support the use of the composite total score (out of 100); there is evidence however to evaluate the individual components of the SCAT3 (balance testing, post concussive symptoms etc.), which have for the most part remained the same as the SCAT2. One additional test recommended (but not required) to the balance examination is tandem gait. The athlete is directed to walk heel/toe along a line of tape 3 metres long turn around and walk back. Athletes should complete the test in 14 seconds. This tandem gait is a pass/fail test aimed to improve the sensitivity of balance testing…but as always more research is needed. From a practical standpoint it is now recommended for field therapists to wait 15 minutes on the sidelines before conducting the post concussive symptom and severity checklist, neurocognitive function tests and balance tests. A paediatric SCAT3 has also been added to be used for 5-12 year olds.

If you have any other questions, comments or concerns regarding the most recent Zurich consensus statement please email us at info@theproactiveathlete.ca or post a question or comment on our facebook page.

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