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:
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:
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.
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 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.
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.