Introduction: The CDC defines concussion as “a type of traumatic brain injury—or TBI—caused by a bump, blow, or jolt to the head or by a hit to the body that causes the head and brain to move rapidly back and forth. This sudden movement can cause the brain to bounce around or twist in the skull, stretching and damaging the brain cells and creating chemical changes in the brain,” and estimates up to 3.8 million instances of Sport-Related Concussion (SRC) per year.  Additionally, due to the variability in symptom presentation, the subjective nature of symptom reporting, and widespread misunderstanding about what a concussion actually is, there is an increased need for more objective assessments for detecting SRC in real-time.

Clinical Scenario: A 17 year-old female varsity soccer captain suffers a head injury early in the 2^nd quarter of the game.  She does not lose consciousness, is able to walk off the field and is A&O x3.  She is, however, reporting nausea, grogginess and tinnitus.  Her parents and coaches are pushing to have the athlete return to the game, as she is one of the star athletes.  Feeling pressured, and anxious to return to play, the athlete informs the Athletic Trainer that she feels “ok” and can return to the game.  The Athletic Trainer, seeing mixed signs and symptoms, decides to further screen the athlete for concussion before making a decision on return to play.

PICO: In the school-aged athlete, how accurate are standardized assessments in detecting concussion immediately following head injury?

Search Strategy:

• Inclusion Criteria: (1) Studies must be relevant to school-aged athletes (<25yo); (2) Concussion Assessment must be applicable to sideline evaluations or immediately post-injury.
• Exclusion Criteria: (1) Concussion Assessments given only >24 hours post-injury (studies were included if they included both < and > 24 hours)
• Keywords: The following key words were used in various combinations to search PubMed, CINAHL, and PEDro Databases: Visual Motor, Sports, Concussion, Sideline, Sport Concussion Assessment.

Results:
 

Limitations:

• Majority Male Samples
• Sport studied was majority football
• Lack of agreed upon reference standards used, with inconsistent reporting on how concussion diagnosis was confirmed.
• Index screening commonly done after athlete was concussion was diagnosed on the sideline.
• Inconsistent reporting on environment in which baseline and post-season measures were taken.

Clinical Bottom Line:  There is consistent Level 2-3 evidence that the SCAT3 is a moderately reliable tool for detecting concussion.  Baseline testing is still recommended for the SCAT3, as there has not been enough research to back the use of normative data.  There is consistent Level 3 evidence that the King-Devick Test is a reliable tool for detecting concussion in the presence of both a concussive-force injury, and an accumulation of sub-concussive impacts.  The King-Devick Test is a quick and low-cost assessment; however, due to lower levels of evidence and small sample sizes, further study is needed to confirm reliability and validity.

Application of the Evidence:  As there have been no adverse effects reported with either sideline test, I would proceed with screening my athlete.  Given the lower Test-Retest Reliability of the SCAT3, as well as the subjective and self-reported nature of some of the components, paired with the pressure from the coach and parents to return to play, I would not choose the SCAT3 for this athlete.  I believe The King-Devick Test provides a more objective and more reliable screening in this case.

References:

1. Seidman D, Burlingame J, Yousif L et al. Evaluation of the King–Devick test as a concussion screening tool in high school football players. Journal of the Neurological Sciences. 2015;356(1-2):97-101. doi:10.1016/j.jns.2015.06.021.
2. Chin E, Nelson L, Barr W, McCrory P, McCrea M. Reliability and Validity of the Sport Concussion Assessment Tool-3 (SCAT3) in High School and Collegiate Athletes. The American Journal of Sports Medicine. 2016;44(9):2276-2285. doi:10.1177/0363546516648141.
3. King D, Hume P, Gissane C, Clark T. Use of the King–Devick test for sideline concussion screening in junior rugby league. Journal of the Neurological Sciences. 2015;357(1-2):75-79. doi:10.1016/j.jns.2015.06.069.
4. Galetta K, Brandes L, Maki K et al. The King–Devick test and sports-related concussion: Study of a rapid visual screening tool in a collegiate cohort. Journal of the Neurological Sciences. 2011;309(1-2):34-39. doi:10.1016/j.jns.2011.07.039.
5. Yengo-Kahn A, Hale A, Zalneraitis B, Zuckerman S, Sills A, Solomon G. The Sport Concussion Assessment Tool: a systematic review. Neurosurgical Focus. 2016;40(4):E6. doi:10.3171/2016.1.focus15611.