Sideline Concussion Assessment Standard: A Review of the Utility of SCAT5

An estimated 1.6-3.8 million sports and recreation-related concussions occur in the United States each year, according to the Brain Injury Research Institute. Sideline physicians properly monitoring and removing athletes from dangerous situations potentially save lives. Severe head injuries are not difficult to identify and triage with the proper level of attention. Mild to moderate head injuries, however, can be subtle or seem insignificant to coaches and players, requiring proper clinical judgement and team-specific concussion protocols to prevent further neurologic damage. There are several tools used on the field when a player sustains a blow to the head or starts acting differently, including the most widely used sideline tool, the Sports Concussion Assessment Tool - 5th Edition (SCAT5). 

The SCAT5 sideline tool was updated in 2017 by the Concussion in Sport Group (CISG) during the 5th International Consensus Conference on Concussion in Sport in Berlin. It is intended for use by medical practitioners and gives guidance on how to approach and monitor suspected concussions. However, it does have its limitations, notably that a player may have a concussion despite having a normal SCAT5 score, and, therefore, clinical judgement should take precedence. The adult SCAT5 has on-field and off-field assessments to categorize severity and follow-up evaluation. It is broken down into subscales, or categories of observable signs and examinations, some of which can be scored individually. The composite scoring system was removed during the update of SCAT2 to SCAT3 in 2012 based on limited evidence supporting its use.

• Step 1 includes easily identifiable red flags: loss of consciousness, severe and increasing headache, seizures, tonic posturing, vomiting, deteriorating alertness, severe neck pain, or weakness. These players should be removed from play and immediately transported to an emergency room.
• Step 2 is to recognize other observable signs including motionlessness, facial injuries, blank stares, disorientation or confusion, and balance or gait difficulties. Most items on this list seem obvious. However, the balance or gait issues occur on a spectrum, and many highly coordinated athletes will have a better ability to compensate for balance loss than other less seasoned athletes. There are several other behaviors that are subtler and may not be recognized without retrospective video analysis, if at all. Research is underway to develop better recognition skills for medical providers, trainers, and other non-medical providers.

Off-site or in-office assessment should be performed on all athletes in the concussion protocol. This secondary assessment should be done in a distraction-free environment because it is long and requires full attention to get an accurate score. This assessment is especially important in distinguishing non-concussed from mild- or moderately-concussed athletes. Ideally, each player would complete this entire assessment in a non-concussed state before play to know their baseline. This would be helpful for higher level athletes that may display better balance or for those with lower cognitive baseline during the Standardized Assessment of Concussion (SAC) (step 3 of the SCAT5).

• Step 3 is a memory test to evaluate the mental status of an athlete. The Child SCAT5 skips this step, presumably because children may not be able to answer these types of questions in a normal state. Questionnaires, in general, are fraught with subjectivity and inaccuracies that make interpretation difficult. However, these are relatively straight-forward and give an idea of whether amnesia is a component of the head injury. Amnesia alone is a less sensitive than specific associated symptom of concussions.
• Step 4 is a basic Glascow Coma Scale (GCS) examination, which evaluates the visual, verbal, and motor responses on a scale of 0-15. This is a crucial component of any trauma assessment, especially in the acute emergency setting, and is intended to be performed serially when monitoring a suspected concussed athlete. This is the only scored section of the on-field assessment process of the SCAT5.
• Lastly, a cervical spine exam is required for all on-field concussion subjects. This exam focuses on neck pain at rest, which is an important distinction from pain with activity for vertebral injuries. Once determining a pain-free state at rest (again, a subjective finding athletes could lie about), range of motion, limb strength, and sensation is evaluated. This is a one-time assessment and a trained medical professional can rule out significant cervical dangers.

The athlete’s medical background is reviewed off-site, so hopefully intellectual disabilities would be recognized at that point. However, both this section and the symptom evaluation checklist are subjective, and the athlete can intentionally withhold information to avoid being taken out of the game.  According to the developers of the SCAT5, the graded symptom checklist, SAC, and modified balance error scoring system (mBESS) were the most useful in distinguishing presence of concussion. The SAC evaluates orientation, immediate memory, and concentration with repeating numbers backwards and months in reverse order. This could easily be skewed by the baseline cognitive function of the athlete. The mBESS tests single, double, tandem leg balance, taking into consideration testing surface and footwear. Still, a stronger or more coordinated individual may test better after a concussion than a non-concussed individual, so again individual circumstances should be considered by the medical professional evaluating the athlete.

Overall, the SCAT5 provides a good basis to decide whether an injured athlete can return to play. When in doubt with clinical suspicion, it is always better to pull the athlete from play and continue evaluation over subsequent days. There are no FDA-approved concussion testing apps on the market currently, though there are numerous apps that are only one component of a concussion diagnosis and management protocol or allow users to record pertinent information regarding a child with a suspected concussion and share that information via email with healthcare professionals. Keeping that in mind, sideline physicians should be wary of the latest app sensations, and use their training to make a sensible clinical judgement call when treating athletes with suspected head injuries.