The currently used injury grading scales and return-to-play guidelines for high school athletes with mild concussions may be too liberal, because they allow athletes to return to play too soon and put them at risk for further injury, says the UPMC sports concussion research team. Current concussion grading systems and return-to-play guidelines should be changed to make them more strict, the researchers add.
The current guideline allows athletes with grade 1 mild concussions to return to play immediately, if on-the-field symptoms disappear within 15 minutes. However, the UPMC study of 43 mildly concussed athletes showed in all but four athletes that either or both memory decline and other symptoms persisted for several days beyond the game in which they were injured, according to principal investigator Mark Lovell, Ph.D., director of the UPMC Sports Medicine Concussion Program.
"The findings of this study are alarming given that the participating athletes did not show clear evidence of on-the-field mental status changes, such as sideline confusion or amnesia lasting longer than 15 minutes, and were reported to be completely symptom-free within this same time period," said Dr. Lovell. "Based on currently used guidelines, all of these athletes potentially could have been cleared to return to play during the game or practice in which they were injured, potentially risking more severe injury."
"Mild concussions, often called, 'dings' or 'bell ringers', are by far the most common type of concussion in high school athletes," said study investigator Michael Collins, Ph.D., assistant director of the UPMC program. "We've proven in recent studies that mild concussions can have significant neurocognitive effects.
Unfortunately, there has been a longtime common assumption in the athletic community that 'having one's bell rung' represents a rapidly resolving injury. This study further challenges that assumption as well as the current grading scale guideline, and clearly demonstrates that even seemingly mild concussions whose symptoms disappear within 15 minutes should be treated as a serious injury and the athletes should not be allowed to return to play in that particular game or practice session," said Dr. Collins.
Each year, a concussion occurs in about one in 10 high school athletes, the population most at risk for mild concussion. Concussion is a trauma-induced alteration in mental status due to the violent rocking back and forth of the brain inside of the skull that occurs with a sudden blow to the head or upper body. Symptoms vary and include amnesia, disorientation, confusion, dizziness, headache, nausea, uncoordinated hand-eye movements, and sometimes loss of consciousness. Previous studies have shown that, generally, an athlete can fully and safely recover from a mild concussion as long as the brain has had time to heal before returning to contact sports. Once an athlete sustains an initial concussion, however, he or she is more susceptible to further, more serious brain damage, worsening of symptoms and a lowered threshold for re-injury.
The UPMC research team evaluated 43 high school athletes with mild concussions, all of whom were symptom-free within 15 minutes of injury, thus classified as having a grade 1 concussion, according to the commonly used American Academy of Neurology concussion severity grading scale. None of the athletes were returned to play prior to completing two post-injury neurocognitive evaluations - the first at 36 hours post injury; the second at day 6 post injury. The evaluation tool used was the ImPACT® (Immediate Post-Concussion Assessment and Cognitive Testing) system, a computerized battery of tests measuring neurocognitive functions such as memory, brain processing speed and hand-eye coordination. All athletes in the study had completed a pre-season baseline ImPACT test and that data was used for comparison to the post-injury ImPACT evaluation data for each athlete.
"We found a clear decline in memory processes and an increase in the self-report of symptoms during the first few days of recovery," said Dr. Lovell. Of the 43 mildly concussed athletes, whose on-the-field symptoms disappeared within 15 minutes, only four did not demonstrate both significantly poorer memory performance on ImPACT and increase of other symptoms at 36 hours post injury. Only seven exhibited normal (equal to or better than baseline) ImPACT test scores at 36 hours post injury, but still had other symptoms; and 11 reported no other symptoms at 36 hours post injury, but still did poorly on ImPACT memory testing. All of the athletes' ImPACT scores returned to normal levels and there was no more increase in other symptoms at day 6 post-injury evaluation.
The average age of the study participants was 15.6 years; 35 were male and eight were female; 24 were injured while playing football; eight, while playing soccer; five, basketball; two, ice hockey; two, lacrosse; one, baseball; and one, softball. They represented high schools in Pennsylvania, Michigan, Illinois, Oregon and Maine. Their concussions under study were sustained during the 2000-2001 school year.
Other investigators in this study include: Grant Iverson, Ph.D., University of British Columbia in Vancouver, Canada; Karen Johnston, M.D., Ph.D., McGill University, Montreal, Canada; and James Bradley, M.D., UPMC.