When a patient shows any potential features of a concussion, the athlete should initially be evaluated by emergency procedures including the ABCs (airway, breathing, and circulation) of emergency care, with a special emphasis on evaluating for a possible cervical spine injury. The disposition based on emergency protocol should be determined by the treating health care provider. A stable patient should next be evaluated by a sideline tool designed for concussion evaluation, such as the Sports Concussion Assessment Tool (SCAT2). After diagnosis of a concussion, a player should not be left alone, with serial monitoring for several hours after the injury. Based on the Zurich consensus, an athlete should not be allowed to return to competition on the same day as the injury (22).

One essential part of sideline evaluation is testing of cognitive function. Standard orientation questions (e.g., time, place, and person) have been shown to be ineffective in sideline evaluations compared to memory assessment (19).

Brief tests for attention and memory function have been shown to be effective, including the Maddocks questions (19) and the Standardized Assessment of Concussion (SAC) (20). These tests are effective for rapid sideline evaluation, but in questions of more subtle, persistent changes, they are not able to replace the effectiveness of comprehensive neuropsychological testing.

The use of neuroimaging studies is still not effective for the standard evaluation of concussions. Brain computed tomography (CT) and magnetic resonance imaging (MRI) are normal in concussive injuries but should still continue to be used when there are symptoms suspicious for possible intracerebral structural lesions. These situations include prolonged disturbance in consciousness, focal neurologic deficits, or worsening symptoms.

Newer studies, including perfusion and diffusion MRIs, functional MRI, positron emission tomography, and magnetic resonance spectroscopy, show some future promise but are still limited by minimal published studies and inability to compare to preinjury imaging.

Objective balance assessment can provide additional information in concussed patients. Studies consistently show, whether by sophisticated force plate testing or clinical balance tests, that postural stability deficits persist for about 72 hours. These tests are useful tools to evaluate the motor portion of neurologic function.

Neuropsychological testing (NP) gives critical information that can be valuable in concussion evaluation and recovery. In some cases, cognitive recovery and symptom recovery follow the same pattern, but studies have demonstrated that frequently cognitive recovery lags behind symptom recovery. In these cases, NP testing would be beneficial in determining which patients are not fully recovered functionally. It is important to recognize that NP assessment should not be used singularly to make return-to-play decisions, but that it is effective as an addition to clinical decision making. Based on the data from several studies, NP testing is best used in return-to-play decisions after the patient is asymptomatic (4).

The main tenet of treatment for concussion is physical and cognitive rest. Complete rest should be encouraged until the symptoms have completely resolved. This includes all physical activity and any activities that involve concentration and attention, including school work, videogames, and texting. All these activities have the potential to exacerbate symptoms and delay recovery. With complete rest, the majority of symptoms will resolve spontaneously within several days.

When symptoms have resolved, the next step is a gradual return to activity. A graduated return-to-play protocol is listed in Table 36.1. The athlete needs to remain asymptomatic to continue along the stepwise progression. Each stage should last for 24 hours. If any postconcussion symptoms develop, the patient should return to the previous asymptomatic stage. The Zurich committee discussed the possibility of some high-level athletes returning on the day of injury. This should only occur in a small population, described as adult athletes in a setting with team physicians experienced in concussion management and access to immediate neurocognitive assessment. This is based on a National Football League (NFL) study showing safe same-day return in some NFL athletes (27). This does not include high school or college-age athletes, because multiple studies have shown that athletes in this age group often continue to show NP deficits despite being asymptomatic on the sidelines and are more likely to have delayed onset of symptoms (6,7).

There are several factors that should cause the physician to consider a more deliberate approach to return to play. One controversial factor is LOC. Although prior guidelines that were primarily based on presence or absence of LOC have been shown to be less helpful, LOC is still an importance indicator of severity. If LOC lasts greater than a minute, that is an indicator of a more severe concussion that will likely require longer recovery time. Presence of amnesia is still difficult to interpret but may correlate with prolonged recovery. Athletes with multiple concussions should be given more time to recover. Athletes with repeated concussions occurring with progressively less impact are likely to require a longer period of recovery.

Several populations require a more vigilant approach to provide effective care. Child and adolescent athletes tend to recover at a slower pace, with a more deliberate resolution of symptoms and return to baseline cognition. The Zurich guidelines were determined to be applicable to athletes 10 years and older. In younger athletes, the symptoms are often interpreted and described differently. It is often helpful to seek input from parents and teachers about concussion effects. It remains important for young athletes to be completely symptom free prior to return to sport, and this often takes a longer period in the developing brain. Cognitive rest is an important emphasis in this age group with the frequent use of computers, videogames, and texting. Students may also benefit from time off from school, studies, and school
activities. Due to the prolonged recovery, in many cases, it is beneficial to extend the length of asymptomatic time until return to sport or to extend the length of each stage of the return-to-play plan. Although females are more prone to concussion, the experts at the Zurich conference determined that there is no need to adjust the evaluation and treatment of female athletes.

Second impact syndrome is one reason for the graduated return to play. This occurs in an athlete who returns to contact before resolution of the symptoms and physiologic changes associated with concussion. A second traumatic event results in loss of cerebral vasomotor control. This results in uncontrollable cerebral edema and increasing intracranial volume and pressure. This often leads to neurologic collapse and death.