Numeric grading scales

Most concussion and return-to-play guidelines issued before 2000 use numeric grading scales and rely on the presence/absence of loss of consciousness (LOC) and post-traumatic amnesia (PTA) to determine the severity of a concussion and return to play (RTP).

None gained universal acceptance or were consistently followed by sports medicine professionals, many of whom ended up not using any grading scale for evaluation or RTP purposes.

Simple versus Complex

Concussion management guidelines issued since 2000 move away from reliance on LOC and PTA as sole predictors of injury severity. They focus instead on the number and duration of all post-concussion signs and symptoms and recognize that severity of injury can only be determined after those signs and symptoms have cleared.

This new approach is best exemplified by the consensus statement issued in 2005 after the 2nd International Conference on Concussion in Sport in Prague held the previous year. Instead of classifying concussions by grade (Grade 1=mild, Grade 2=moderate, Grade 3=severe), the Prague statement classifies concussion as either simple or complex depending on the type, duration and number of symptoms and how long they take to resolve.

Simple concussions (the most common form) progressively resolve without complications over seven to ten days, while a concussion is classified as complex if (a) certain post-concussive symptoms such as convulsions or extended loss of consciousness were present, or (b) symptoms such as cognitive impairment persist beyond 10 days, (c) the athlete has a history of previous concussions, and/or where repeated concussions have occurred with progressively less impact force.

Consensus not unanimity

Experts, even those who participated in the drafting of the Prague statement, do not all necessarily agree with its approach. MomsTeam expert, Dr. Robert Cantu, for one, does not view a concussion with symptoms lasting as long as 10 days as "simple" and considers use of the word "simple" to describe any concussion as unwise.

The yet-to-be-published consensus statement on concussion of the Third International Conference on Concussion in Sport held in St. Moritz, Switzerland in March 2006 is expected to address this important issue.

Loss of Consciousness

Although LOC is not required for an injury to be classified as a concussion (a 2000 study of 1003 concussions sustained by high school and college football players found that only 9% had suffered LOC), most early concussion grading scales viewed the most severe injuries as being associated with LOC.

Recent studies, however, have shown that brief LOC (less than one minute) is not associated with abnormal neuropsychological testing at 48 hours after injury. Studies of high school and college athletes with concussions have also shown a lack of association between LOC and duration of symptoms, and between LOC and neuropsychological and balance tests at 3, 24, 48, 72 and 96 hours postinjury.

As a result, LOC is no longer viewed, by itself or in combination with post-traumatic amnesia (PTA), to connote a severe concussion. This is reflected in the Prague consensus statement, under which the presence of LOC does not necessarily result in classification of a concussion as complex.

Amnesia

The role of post-traumatic amnesia in predicting or measuring injury severity is also being re-evaluated.

Study findings have been inconsistent:

• Older studies of non-athletes (pre-2000) suggest that the duration of PTA correlates with the severity and outcome of severe traumatic brain injury (TBI) but not mild TBI or concussion

• Two more recent studies (2001, 2003) suggest that the presence of amnesia best correlates with abnormal neuropsychological testing at 48 hours post-injury and with the duration and number of other postconcussion signs and symptoms.

• Three 2003 studies of high school and college athletes, however, revealed no association between (1) amnesia and duration of symptoms or (2) amnesia and neuropsychological and balance impairment, 48, 72, and 96 hours after injury.

While these studies also suggest that initial symptom severity (within the first 3 hours) is probably a better indicator than either LOC or amnesia in predicting recovery time, yet another study found that amnesia did predict symptoms and neurocognitive deficits at 2 days post-injury.

Return to Play (Game Day)

Significant controversy exists over whether an athlete should be allowed to return to play on the day of injury:

• Most older (pre-2000) guidelines would permit an athlete to return to the same contest or practice if he has been symptom free for at least 15 to 20 minutes and it is his first concussion of the season (no RTP if second concussion);

• Some disqualify any athlete experiencing LOC or amnesia from returning to play that day and advocate in favor of stricter RTP guidelines for athletes under age 18 years because of the greater risk of catastrophic injury to the maturing brains of youth athletes, and believe that the "safest course of action [is] to hold an athlete out."

• The Prague consensus statement recommends that an athlete experiencing any post-concussion symptoms not be allowed to return to play that day no matter how quickly the symptoms disappear.

• As recently as 2000, nearly one-third (30%) of all high school and collegiate football players sustaining concussions were allowed to return to competition on the same day of injury, with the remaining 70% average 4 days of rest before RTP.

The evidence supports a 7-day waiting period:

• Two 2003 studies suggest that a 7-day waiting period may minimize the risk of another concussion.

• The evidence show that athletes take, on average, 7 days to fully recover after a concussion,

• Same-season repeat injuries typically take place 7 to 10 days after the first, which supports the idea that the brain may more vulnerable to injury during the first 7 days after injury.

Post-Game-Day RTP

All concussion management guidelines, old and new, agree that no athlete should be allowed to return to play while continuing to exhibit any post-concussion signs or symptoms and all call for at least one symptom-free week (or more in the case of more serious Grade 2 or 3 concussions) before RTP.

New concussion guidelines, such as the Prague consensus statement, follow a step-wise RTP approach and take a more individualized approach utilizing progressive aerobic and resistance exercise challenge tests, consideration of the severity of the current injury, the number, severity, and proximity in time of previous concussions, whether the concussion was a result of a minor blow, age, sport, and the athlete's learning disabilities, if any.

Different guidelines for youth athletes

The Prague consensus statement introduced an additional concussion management requirement for children: the concept of "cognitive rest." Because activities that require concentration and attention might exacerbate the symptoms and delay recovery, the statement recommends that child limit exertion with activities of daily living and limit school-related activities until symptom free (e.g. no homework and staying home from school).

The statement also recognized (a) that additional research was needed to better clarify the potential differences between adults and children with regard to recovery from concussion injury, and to develop cognitive assessment tools that better evaluate the young athlete, and (b) that it may be appropriate to extend the amount of time of asymptomatic rest and/or the length of the graded exertion in children and adolescents because of the "different physiological response during childhood to head trauma."

According to Dr. Cantu, the consensus statement that is expected to be issued as a result of the 3rd International Conference on Concussion in Sport held in St. Moritz in 2006 may vary significantly from the Prague statement in its recommendations for management of concussions in children.

Author: Lindsay Barton
Date created: January 22, 2008
© MomsTeam.com, Inc.

Related Articles

 Second Impact Syndrome: What Is It?
 Concussion Severity & Return to Play: Prague Consensus Statement
 The Balance Error Scoring System
 Post Traumatic Amnesia

For more on this topic

 Post-Concussion Signs & Symptoms: A Checklist
 Retrograde and Post-Traumatic Amnesia: What Are They?
 Standardized Concussion Assessment Tool

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