Sports-Related Concussion (SRC)

The most obvious disturbance of brain function with a concussion is:

• Loss of consciousness

However, many patients do not lose consciousness but instead manifest symptoms and signs such as:

• Confusion or disorientation: Appears dazed or stunned, is unsure of opponent or score, answers slowly

• Memory loss: Does not know plays or assignment, does not recall events before the injury (retrograde amnesia) or afterward (anterograde amnesia)

• Vision disturbance: Has double vision or light sensitivity

• Dizziness, clumsy movements, impaired balance

• Headache

• Nausea and vomiting

• Tinnitus

• Loss of smell or taste

Duration of symptoms from SRC vary, but most studies show resolution largely within a few days to a month (1, 2).

Postconcussive symptoms are symptoms that may be present for a few days to weeks after concussion; they include:

• Chronic headaches

• Short-term memory difficulties

• Difficulty concentrating

• Fatigue/somnolence

• Sleep disturbance

• Emotional lability

• Personality changes (eg, irritability, mood swings)

• Sensitivity to light and noise

Postconcussive symptoms typically resolve in a few weeks to several months.

• History and physical examination

• Sometimes neuroimaging to exclude more serious injuries

Athletes with possible concussion should be evaluated by a clinician with experience in evaluation and management of concussions. Sometimes such clinicians are on site at high-level athletic events; otherwise, sideline staff should have training in recognizing concussive symptoms and protocols for referring patients for evaluation.

Diagnostic tools, such as the Standardized Assessment of Concussion (SAC) or the Sports Concussion Assessment Tool, 6th edition (SCAT6), can help coaching staff, trainers, and inexperienced clinicians screen athletes aged 13 years and older on-site. SCAT6 is currently the most commonly used clinical instrument and is endorsed by many professional bodies such as International Association Football Federation (FIFA), National Football League (NFL), and World Rugby. The major limitation is that it cannot effectively be used on-field or on the sidelines to determine whether the athlete needs to be removed from play (usually due to rules limiting duration of game stoppage).

Neuroimaging is not helpful to diagnose concussion itself but is done if more serious brain injury (eg, hematoma, contusion) is suspected. Typically, CT or MRI should be done if patients have any of the following:

• Loss of consciousness

• Glasgow Coma Score (GCS) < 15 (see table Glasgow Coma Scale)

• A focal neurologic deficit

• Persistently altered mental status

• Other signs of deterioration

Formal neurocognitive testing can likely show abnormalities in symptomatic patients but is not typically done unless postconcussive symptoms last longer than expected or the patient has severe cognitive problems. Some athletic programs do baseline neurocognitive tests on all participants and repeat them after concussion so that more subtle abnormalities can be identified and further participation deferred until the person returns to baseline.

Clinical Calculators

Glasgow Coma Scale

• Removal from contest or activity

• Rest

• Acetaminophen for headache

• Graduated increase to full athletic activity

Patients who had any concussive symptoms or signs should not return to play that day and are advised to rest for 24 to 48 hours. School and work activities, driving, alcohol, excessive brain stimulation (eg, using computers, television, video games), and physical exertion should be avoided during early recovery to prevent prolongation or exacerbation of the symptoms (1).

Unfortunately, many athletes with concussion do not seek medical evaluation. Concussion can result in a series of underlying neuropathophysiologic changes which, in some cases, can lead to long-term cognitive, behavioral, and psychosocial impairment (2). While no medications have been shown to improve recovery from concussion, specific symptoms can be treated with appropriate medications. For example, preferably acetaminophen, or alternatively nonsteroidal anti-inflammatory drugs (NSAIDs) may be given for headache.

Family members are advised to watch for signs of deterioration and take the person to the hospital if they occur. These signs include:

• Decreased level of consciousness

• Focal neurologic deficits (eg, hemiparesis)

• Worsening headache

• Vomiting

• Deterioration of mental function (eg, seems confused, cannot recognize people, behaves abnormally)

• Seizures

Most patients recover fully, although postconcussive symptoms can persist for up to several months.  Risk factors for chronic neurobehavioral impairment include repetitive concussion exposure and APOE ε4 genotype (1).

There is increasing evidence suggesting that repetitive concussion can lead to chronic traumatic encephalopathy (CTE), a progressive neurodegenerative disease (2). CTE causes progressive brain dysfunction typically leading to death within 10 to 15 years of initial presentation.  In a postmortem study of 202 brains of deceased American football players of all ages and levels,found that CTE neuropathology, was found in 87%, including 110 of 111 former NFL players (3).