Because adolescent athletes judge their readiness to return to play following a concussion based primarily on subjective symptoms, such self-reports should not be used as the sole factor in return-to-play decisions, say researchers at the University of Pittsburgh Medical Center.1
Researchers found that, when athletes gauge their own readiness to return-to-play, they rely most heavily on the absence of somatic (e.g. physical) symptoms such as headache, vomiting and visual disturbances - which are more apparent and easier for the athlete or those around them to directly observe - and much less on the more elusive and subtle symptoms of concussion such as "fogginess," difficulty concentrating or remembering, and slowed reaction time - symptoms which are harder for the athlete to detect. They also found that athletes' awareness of their cognitive decline after concussion is limited.
"The results of the study indicate youth athletes are basing their perceptions of recovery from concussion primarily on overt, physical symptoms such as headache and nausea, and may neglect to consider the cognitive symptoms of the injury, says lead author Natalie Sandel, B.S., of the Department of Neuroscience and Dietrich School of Arts and Sciences at the University of Pittsburgh.
"Relying solely on adolescents' self-reported symptoms for return-to-play and concussion management decisions is ill-advised as their perceptions may include only a small subset of the deficits commonly seen after concussion. These findings further highlight the importance of using objective measures for the assessment of concussion," Sandel says.Indeed, notes sports concussion neuropsychologist and MomsTEAM expert Rosemarie Scolaro Moser, PhD, in her new book, Ahead of the Game, it is such unreliability that is the basis for a "widespread belief among medical professionals that athletes should not be returned to play after a suspected concussion, based solely on the likelihood that self-reporting is unreliable."
"Sports medicine practitioners should be cautious when considering athletes' self-reported symptoms in their return-to-play decisions," Sandel writes. Because "adolescent athletes are considered a high-risk population for sustaining an additional injury or long-term damage following sports-related concussion, it is crucial for practitioners to prevent symptomatic athletes from returning to play. To ensure a more cautious return-to-play decision, a multidisciplinary approach [as recommended in the most recent international consensus statement of concussion experts5] that includes objective neurocognitive testing is advised," she says.
"These research results affirm what we see daily in our clinical experience," said Michael "Micky" Collins, Ph.D., the Concussion Program's executive and clinical director. "Athletes have a hard time understanding the cryptic nature of this injury, and relying only on self-assessment of symptoms is dangerous and naïve when it comes to allowing athletes back to play after a brain injury. Objective assessment through the use of computerized neurocognitive testing and a thorough evaluation are critical components of concussion management and return-to-play considerations."
Collins' view was echoed by study co-author, Mark R. Lovell, Ph. D., FACPN, then with the Pitt Department of Orthopaedic Surgery. "Neurocognitive testing provides a more objective method of measuring recovery from concussion and represents a valuable component of the return to play decision making process. Neurocognitive testing represents an important tool in the toolbox when clinicians are faced with making difficult return to play decisions."
Post-exertion neurocognitive testing recommended
A more recent study6 provides additional support for the view that athletes should not be returned to play based solely on reporting being asymptomatic. It found that, among concussed student-athletes who reported no symptoms and had returned to baseline on computerized neurocognitive tests taken before beginning a graduated return to sports protocol,5 more than a quarter (27.7%) exhibited declines in verbal and visual memory on the tests following moderate exercise.
The findings prompted the study's authors, led by sports concussion neuropsychologist Neal McGrath, Ph.D. of Sports Concussion New England, to recommend that neurocognitive testing become an "integral component of the athletic trainer's post-exertion evaluation protocol and that student-athletes should not be cleared for full contact activity until they are able to demonstrate stability, particularly in memory functioning, on such post-exertion neurocognitive concussion testing."
Males and females in the study showed significant differences in how they feel after sustaining a concussion, with males tending to report greater recovery from their concussions than females, but at the same time considering a greater number of factors in their self-report assessments of recovery from concussion. The findings, said the authors, suggest that females may experience more severe post-concussion symptoms than males (a view supported by several recent studies2,3,4 and generally consistent with what Sandel and Lovell say they see in clinical practice), or that males under-report their symptoms.
Despite the breadth of literature on differences in the presentation of concussion in males and females, there is limited research rationalizing why these differences are observed, says Sandel. Are males underreporting symptoms or do they experience less severe postconcussion symptoms and does this reflect cultural issues (i.e., male machismo)? Do females lack insight into their injuries or is their experience of concussion completely different from that of males? Future research is needed to answer these questions.
She notes that several studies have examined sex differences in neurocognitive test performance but yielded inconsistent results. Some studies indicate females perform worse overall, whereas others suggest females may outperform males on tasks measuring verbal memory.3,4 To further complicate the matter, a 2010 study demonstrated that a history of concussion affects males' and females' performances on neurocognitive testing differently. Therefore, although the current study supported previous findings of sex differences in concussion, additional research investigating why these differences occur is needed, Sandel says.
The research team studied 101 concussed athletes (62 males, 39 females) ages 12 to 18, who were evaluated by clinicians at the UPMC Center for Sports Medicine Concussion Program. They asked athletes to rate their "percent back to normal." They compared those numbers against the ImPACT (Immediate Post-Concussion Assessment and Cognitive Testing) battery and somatic, cognitive, sleep and neuropsychiatric symptom clusters to find significant correlations. In short, the athletes' judgment was based on a small subset of the factors evaluated in concussion care.
Source: University of Pittsburgh Medical Center
1. Sandel N, Lovell M, Kegel N, Collins M, Kontos A. The Relationship Of Symptoms and Neurocognitive Performance to Perceived Recovery From Sports-Related Concussion Among Adolescent Athletes. Applied Neuropsychology: Child. 2012; DOI:10.1080/21622965.201 2.670680 (published online ahead of print 22 May 2012)(accessed June 5, 2012)
2. Covassin T, Elbin R, Harris W, Parker T, Kontos A. The Role of Age and Sex in Symptoms, Neurocognitive Performance, and Postural Stability in Athletes After Concussion. Am. J. Sports Med. 2012;20(10); published on April 26, 2012 at DOI:10.117703654651244454
3. Colvin AC, Mullen J, Lovell MR, West RV, Collins MW, Groh M. The Role of Concussion History and Gender in Recovery from Soccer-Related Concussion. Am. J. Sports Med. 2009;37(9): 1699-1704.
4. Covassin, T, Elbin, R.J., Larson, E., & Kontos, A.P. Sex and age differences in depression and baseline sport-related concussion neurocognitive performance and symptoms. Clinical Journal of Sports Medicine 2012;22(2):98-104.
5. Concussion Statement on Concussion in Sport: the 3rd International Conference on Concussion in Sport held in Zurich, November 2008, P. McCrory et. al, Br. J. Sports Med. 2009; 43; i76-i84.
6. McGrath N, Dinn WM, Collins MW, Lovell MR, Elbin RJ, Kontos AP. Post-exertion neurocognitive test failure among student-athletes following concussion. Brain Injury 2013;27(1):103-113.
Posted June 15, 2012; revised July 10, 2012 to include Dr. Moser's comment; revised February 7, 2013 to include study in Brain Injury (footnote 6).