Patient symptom report remains the most accurate method of sport concussion assessment
By Ella Webster. This article was initially published in the 7/25/24 edition of our Concussion Update newsletter; please consider subscribing.
In a case-control study published in JAMA Network, Kimberly G. Harmon et al. found that an athlete’s symptom report is more accurate for concussion diagnosis than the Standardized Assessment of Concussion (SAC), a cognitive evaluation commonly used as part of the Sports Concussion Assessment Tool (SCAT). The SCAT is used for evaluation in sports and encompasses both the subjective symptom report and the SAC, which screens for signs of cognitive dysfunction commonly seen in concussion patients. Researchers analyzed the components of SCAT-5 baseline results and post-injury SCAT-5 for 92 NCAA athletes who suffered a concussion while playing their sport. Many of the studied athletes had inconsistent SAC scores while a concussion was present, highlighting the importance of the symptom report.
When a concussion was suspected, athletes were screened with the SCAT-5 within 48 hours, including the SAC––using a 10-word list to test memory and recall introduced in the SCAT-5 after criticisms of previous versions’ 5-word list. If a concussion was confirmed, a control athlete underwent the same tests. Each concussed athlete was matched to a non-injured control athlete of the same gender, age, sport, and a baseline SCAT-5 score within 2 points. Researchers found that SAC had poor diagnostic utility regarding sensitivity and specificity even using the 10-word list, whereas reported symptoms were more accurate in both sensitivity and specificity. Concerningly, 45% of athletes with a concussion scored at or above their baseline SAC (within normal limits), despite a score below baseline indicating concussion. Although a score at or above baseline SAC may be inconclusive, the fact that the SAC did not identify almost half of the concussions highlights the importance of the symptom report and the lack of accuracy of the SAC cognitive examination. The study authors add that in addition to the symptom report (typically an increase in symptoms), “other objective indicators of concussion such as visual signs and vestibulo-ocular or balance abnormalities” are an important part of concussion diagnosis. One of the limitations of the study noted by the authors is that the variance between sets of 10-word lists used for the SAC was not monitored, despite a previous study showing that these lists varied in difficulty.
In areview article by Sophie Dorey with The Daily, Harmon expresses the importance of a rounded approach, “The takeaway is if you get hit in the head and you have a headache, you’re dizzy, and you don’t feel right — that’s a concussion even if you do normally on the [SAC],” Harmon said. “You have to look at the big picture.” Harmon emphasizes the continuous use of a multimodal approach to concussion diagnosis for athletes.
