, a new study showed.
Investigators found that almost half of athletes diagnosed with a concussion tested normally on the Sports Concussion Assessment Tool 5 (SCAT5), the recommended tool for measuring cognitive skills in concussion evaluations. The most accurate measure of concussion was symptoms reported by the athletes.
“If you don’t do well on the cognitive exam, it suggests you have a concussion. But many people who are concussed do fine on the exam,” lead author Kimberly Harmon, MD, professor of family medicine and section head of sports medicine at the University of Washington School of Medicine, Seattle, said in a news release.
The study was published online in JAMA Network Open.
Introduced in 2004, the SCAT was created to standardize the collection of information clinicians use to diagnose concussion, including evaluation of symptoms, orientation, and balance. It also uses a 10-word list to assess immediate memory and delayed recall.
Dr. Harmon’s own experiences as a team physician led her to wonder about the accuracy of the cognitive screening portion of the SCAT. She saw that “some people were concussed, and they did well on the recall test. Some people weren’t concussed, and they didn’t do well. So I thought we should study it,” she said.
Investigators compared 92 National Collegiate Athletic Association (NCAA) Division 1 athletes who had sustained a concussion between 2020 and 2022 and had a concussion evaluation within 48 hours to 92 matched nonconcussed teammates (overall cohort, 52% men). Most concussions occurred in those who played football, followed by volleyball.
All athletes had previously completed NCAA-required baseline concussion screenings. Participants completed the SCAT5 screening test within 2 weeks of the incident concussion.
No significant differences were found between the baseline scores of athletes with and without concussion. Moreover, responses on the word recall section of the SCAT5 held little predictive value for concussion.
Nearly half (45%) of athletes with concussion performed at or even above their baseline cognitive report, which the authors said highlights the limitations of the cognitive components of SCAT5.
The most accurate predictor of concussion was participants’ responses to questions about their symptoms.
“If you get hit in the head and go to the sideline and say, ‘I have a headache, I’m dizzy, I don’t feel right,’ I can say with pretty good assurance that you have a concussion,” Dr. Harmon continued. “I don’t need to do any testing.”
Unfortunately, the problem is “that some athletes don’t want to come out. They don’t report their symptoms or may not recognize their symptoms. So then you need an objective, accurate test to tell you whether you can safely put the athlete back on the field. We don’t have that right now.”
The study did not control for concussion history, and the all–Division 1 cohort means the findings may not be generalizable to other athletes.
Nevertheless, investigators said the study “affirms that reported symptoms are the most sensitive indicator of concussion, and there are limitations to the objective cognitive testing included in the SCAT.” They concluded that concussion “remains a clinical diagnosis that should be based on a thorough review of signs, symptoms, and clinical findings.”
This study was funded in part by donations from University of Washington alumni Jack and Luellen Cherneski and the Chisholm Foundation. Dr. Harmon reported no relevant financial relationships.
A version of this article first appeared on Medscape.com.