Diagnosing and Treating Sports-Related Concussion

The Centers for Disease Control and Prevention estimate that approximately 1.6 million to 3.8 million sports-related concussions occur annually in the United States, although the true incidence is probably much higher. Under-reporting may be due to the fact that athletes, coaches, trainers, family and even some health care professionals are unaware of the symptoms and treatment options for concussion. And athletes who experience concussion sometimes fail to report their symptoms to avoid losing playing time.

Concussions that are unrecognized or are mismanaged put athletes at considerable risk of potentially catastrophic sequelae from re-injury. Repetitive head trauma from participation in contact sports such as boxing, football and ice hockey can lead to a permanent decrease in brain function, including:

• Memory loss
• Early Alzheimer's disease
• Movement disorders such as parkinsonism
• Emotional disturbances

The most notable complication of concussion is second impact syndrome. In this syndrome, an athlete who is recovering from an initial concussion sustains a subsequent concussive injury, resulting in diffuse brain swelling and severe, permanent neurological dysfunction or death.

Standard neuroimaging studies are typically normal; therefore, concussion is a clinical diagnosis. The most common symptom is headache. Other signs and symptoms include:

• Dizziness
• Nausea
• Vomiting
• Balance problems
• Fatigue
• Sleep disturbance
• Sensitivity to light and noise
• Mood changes
• Difficulty with concentration and memory

Each concussion presents in a unique manner, and it is well established that a concussion does not require a loss of consciousness. Furthermore, a brief loss of consciousness does not provide any information regarding concussion severity. What clinicians need to remember is that if an athlete sustains a blow to the body or head and post-concussive symptoms subsequently develop, by definition, that athlete has sustained a concussion.

Understanding who is at risk

Athletes who engage in contact sports and female athletes are at increased risk of concussion. Young athletes may be more susceptible than are adults to concussions due to a larger head-to-body-size ratio, weaker neck muscles or increased vulnerability of the young brain to concussion.

Timely diagnosis and treatment

Mayo Concussion Test and Post-Concussion Symptoms Scale

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Timely diagnosis and prompt treatment can help prevent more-serious concussion complications. Obtaining pre-injury baseline data on athletes who engage in contact sports can make the sideline assessment more accurate. Mayo Clinic's Sports Medicine Center performs baseline testing on high school athletes involved in high-risk sports as part of their preseason physicals.

Baseline assessments include a brief cognitive test (the Mayo Concussion Test), a computer-based neuropsychological test, and the Post-Concussion Symptoms Scale.

These data are available during games and in the clinic and provide medical personnel with a pre-injury reference point from which to judge an athlete's status following a concussion. If a concussion is suspected, Mayo Clinic sports medicine specialists follow a protocol for evaluating and treating athletes of all ages.

Protocol for evaluating and treating suspected concussion

• Remove the athlete from competition immediately and do not allow him or her to resume play for the remainder of the game.
• Perform the Mayo Concussion Test and the Post-Concussion Symptoms Scale on-site and compare the results with the athlete's baseline data.
• Monitor for worsening of symptoms and/or focal neurologic deficits, including weakness and sensory change, every 15 to 30 minutes during the first several hours after injury.
• If symptoms worsen, the athlete should be transported to an emergency department for further evaluation, because changes may suggest an injury more serious than a concussion, such as intracranial hemorrhage.
• If symptoms remain stable or improve, the athlete can be sent home if an adult caregiver is present. The caregiver is given a list of symptoms to be aware of and that would warrant a trip to an emergency department, and the athlete is not allowed to drive.
• Place the athlete on physical (no sports, running, jumping, or weightlifting, for example) and cognitive (no school, studying, or video games, for example) rest to minimize stress on the brain.
• Have the athlete follow up with his or her physician within 24 to 48 hours for a physical examination and symptom evaluation, as well as additional cognitive testing.

Resuming athletic activity

Once an athlete is asymptomatic and has normal neuropsychological measures, he or she can begin a functional return-to-play process. This process involves gradually increasing cognitive and physical challenges in a systematic, stepwise fashion, over the course of about five days. If the athlete has symptoms at any time, he or she rests again until the symptoms stop. Then the athlete can resume the protocol on the level at which he or she was symptom-free.

Mayo Clinic sports medicine specialists monitor symptomatic athletes for up to two weeks, at which time athletes who remain symptomatic are referred to the Mayo Clinic Complex Concussion Team, comprising a brain rehabilitation specialist, occupational and speech therapists, a rehabilitation nurse, a neuropsychologist, and other health care professionals as indicated.

The team manages the athlete's post-concussion symptoms and assists with modifications in work and school that are required for recovery. When the athlete's symptoms resolve and all baseline measures return to normal, he or she resumes the return-to-play protocol under the supervision of Mayo Clinic's Sports Medicine Center staff.

Points to remember

• A concussion does not require a loss of consciousness. If an athlete sustains a blow to the body or head and post-concussive symptoms subsequently develop, by definition, that athlete has sustained a concussion.
• Obtaining pre-injury baseline data on athletes who engage in contact sports can make sideline assessment more accurate.
• Timely diagnosis and prompt treatment can help prevent more-serious concussion complications, including diffuse brain swelling and severe, permanent neurological dysfunction or death brought on by subsequent concussive injury.