In the wake of recent reports of long-term health effects of repeated concussions in professional athletes, a new study finds increased rates of concussion-related symptoms in high school athletes with a history of two or more previous concussions [Neurosurgery, online, Jan. 25, 2011].
The study was led by Philip Schatz, PhD, professor of psychology at Saint Joseph's University, in Philadelphia, PA, a consultant with the International Brain Research Foundation, in Edison, NJ, and director of neuropsychology research at the Sports Concussion Center of New Jersey. Collaborators were Rosemarie Scolaro Moser, PhD, Tracey Covassin, PhD, ATC, and Robin Karpf, MD.
The findings suggest that some teen athletes with multiple concussions already may have early signs of post-concussion syndrome. "It appears that youth athletes who sustain multiple concussions experience a variety of subtle effects, which may be possible precursors to the future onset of concussion-related difficulties," the researchers stated.
The study was based on more than 2,500 high school athletes in three states. As part of routine pre-season evaluations, all students were evaluated using a standard questionnaire regarding concussion-related symptoms. Rates of different types of symptoms were assessed for 260 athletes reporting one previous concussion and 105 athletes with two or more previous concussions, compared to a random sample of 251 athletes with no previous concussions. None of the athletes had sustained a concussion within the past four months.
The results showed higher rates of concussion-related symptoms in athletes with previous concussions, especially those with two or more concussions. After adjusting for other factors, athletes with two or more concussions were found to have higher ratings for three symptom clusters:
cognitive symptoms, such as feeling "mentally foggy" or having trouble remembering things;
physical symptoms, such as headache, balance problems or dizziness; and
sleep symptoms, such as sleeping more or less than usual.
These symptoms were not significantly different for athletes with one versus no concussions. There were no differences in emotional symptoms, such as irritability or sadness.
Recent reports have highlighted the cognitive and psychological after-effects of repeated concussions, including cases of chronic traumatic encephalopathy (CTE) and degenerative brain disease in retired football players and other athletes. "As a result of these findings, there is concern that repeated concussions can result in brain pathology that leads not only to cognitive difficulties but to serious emotional sequelae in later life," the researchers wrote.
Recently, researchers confirmed the first case of CTE in an 18-year-old football player, who had autopsy brain abnormalities similar to those in retired athletes. "These troubling findings beg the question of whether high school athletes with a history of repeated concussions may also be exhibiting the reported cognitive, emotional, physical and behavioral symptomatology as seen in retired professional athletes with CTE," the new report stated.
The new results show "subtle, yet significant increases" in concussion-related symptoms among high school athletes with two or more concussions. However, Dr. Schatz and colleagues emphasized that their findings do not reflect any direct causal relationship. For example, it may be that athletes with multiple concussions are "simply more sensitive to physical, cognitive and emotional fluctuations."
While further research is ongoing, the researchers believe their findings should "serve as a caution for parents, coaches and sports medicine personnel supervising high school and other youth athletes with a history of concussion. Furthermore, these results support the recent surge in advocacy on state and federal governmental levels to establish youth concussion management programs and to better regulate the rules of youth sports."