When an athlete shows any signs of a concussion, he or she should be medically evaluated on the field or sideline, with particular attention given to ruling out a cervical spine injury. Once the first aid issues are addressed, then an assessment of the athlete's mental status can be made by athletic trainers, coaches, and sideline medical personnel using the Standardized Assessment Of Concussion (SAC).
The SAC takes approximately 5 minutes to administer and includes measures of:
- Orientation (month, date, day of week, year, time)
- Immediate memory (recall of 5 words in 3 separate trials)
- Neurologic screening
- Loss of consciousness (occurrence, duration)
- Amnesia (either retrograde or anterograde) (recollection of events pre- and post-injury)
- Sensation
- Coordination
- Strength
- Concentration
- Exertional maneuvers (jumping jacks, sit-ups)
- Delayed recall (5 words)
Recent studies have shown that the use of the SAC has value in helping sports medicine professionals in the diagnosis and management of concussion in athletes on the sport sideline, particularly in identifying concussions in the 90 to 95% of cases where there is no loss of consciousness or other obvious signs of concussion. The SAC has not, however, been validated for use in the grade school athlete.1
Can't detect impairment from sub-concussive blows
In addition, because it tests for verbal visual memory, the SAC cannot identify athletes who may suffer measurable impairment of neurocognitive function (primarily visual working memory) on neurocognitive tests, as well as altered activation in neurophysiologic function on sophisticated brain imaging tests (fMRI), from repeated sub-concussive blows to the head. As Larry Leverenz, Ph.D, ATC, a co-author of the groundbreaking 2010 study2 that was the first to identify such athletes noted, because they have not suffered damage to areas of the brain associated with language and auditory processing, are unlikely to exhibit clinical signs of head injury (such as headache or dizziness), or show impairment on sideline assessment for concussion, all of which test for verbal, not visual memory, so "there is no way right now to identify" the group suffering sub-concussive blows to the head that may be dangerous.
Follow-up testing required
The SAC is designed for rapid concussion evaluation on the sidelines. Like other brief neuropsychological test batteries that assess attention and memory function, the SAC is not meant to replace comprehensive neuropsychological testing or used as a stand-alone tool for the ongoing management of sports concussions. It is also important to remember that symptoms may not appear until several hours after injury.3
This is especially true because some symptoms, especially in the neurobehavioral category (sleeping more than usual, drowsiness, fatigue and nervousness) are often missed or not aparent on an a sideline or initial assessment, or, where reported by female athletes, may be more attributed to other conditions, such as stress, depression, or anxiety.4
Baseline test data increases effectiveness
As with other neuropsychological testing tools, the value of the SAC in concussion assessment is maximized when individual baseline test data is available because, without such baselines, the athlete's postinjury performance on neuropsychological testing and other concussion assessment measures, such as the SAC, must be interpreted by comparison with a generalized "normal" based on a large population sample.
1. Halstead, M, Walter, K. "Clinical Report - Sport-Related Concussion in Children and Adolescents" Pediatrics. 2010;126(3): 597-615.
3. Talavage T, Nauman E, Breedlove E, et. al. Functionally-Detected Cognitive Impairment in High School Football Players Without Clinically-Diagnosed Concussion. J Neurotrauma. 2010; DOI: 10.1089/neu.2010.1512.
4. Frommer L, Gurka K, Cross K, Ingersoll C, Comstock R.D., Saliba S. "Sex Differences in Concussion Symptoms of High School Athletes" Journal Ath. Training 2011; 46(1):000-000.
