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Concussions, considered a type of mild traumatic brain injury (TBI), are increasing in incidence in both adult and pediatric populations.1,2 Concussions can occur as the result of motor vehicle accidents, falls, occupational accidents, recreational accidents, and assaults. The Centers for Disease Control and Prevention (CDC) estimates that between 1.6 and 3.8 million concussive injuries related to sports occur in the United States annually.3 As the number of emergency department visits for concussion-related injuries increases, so does the demand for primary care providers competent in the evaluation and management of concussions during both the initial presentation and clinical follow-up.
The 4th International Conference on Concussion in Sport, held in 2012, agreed upon the following definition of concussion: “an injury involving a complex pathophysiological process affecting the brain, induced by traumatic biomechanical forces.”4 A concussive head injury can be characterized by the following features: (1) It originates with a direct blow to the head or to another part of the body with transmission of an “impulsive” force to the head; (2) the rapid onset of transient neurologic impairment follows spontaneously; (3) the symptoms largely reflect a functional disturbance rather than a structural injury, with no abnormality seen on standard structural neuroimaging studies; (4) variable clinical symptoms may not include loss of consciousness; and (5) symptom resolution typically follows a sequential course but may be prolonged in a small percentage of cases.4
Because concussion remains a clinical diagnosis, recognition of the typical symptoms and signs (Table 1) is fundamental to initiating management promptly. The hallmark symptoms that a patient typically describes are confusion and amnesia, occasionally with but often without loss of consciousness.5 Symptoms may manifest immediately after the head injury or appear several minutes later.6 The victim usually retains a memory of the traumatic event, but loss of recollection of the events before (retrograde amnesia) and after (anterograde amnesia) the head trauma is frequent. Other early symptoms of concussion include headache, dizziness (vertigo or imbalance), and nausea with or without vomiting.6 Throughout the next several hours or days, the patient may experience cognitive and mood disturbances, photophobia, hyperacusis, or sleep disturbances.7
It is important to note that in many cases, a concussion is not associated with any pertinent examination findings. However, some typical signs may be the following: vacant stare, inability to focus, disorientation, slurred speech, memory deficits, gross observable incoordination, and delayed verbal expression.6 Lastly, posttraumatic seizures typically occur in fewer than 5% of concussion injuries and are more commonly seen in patients with severe TBI.8 In the typical clinical course, a concussion resolves within a short period (7–10 days).4
It is important that any patient in whom a concussion or a mild TBI is suspected be medically evaluated immediately, whether in a physician’s office or hospital emergency department or on the sideline of an athletic event. Evaluation of an acute injury should include a comprehensive history, determination of the mechanism of injury, mental status testing, and a detailed neurologic assessment. “Red flag” signs and symptoms, such as prolonged loss of consciousness, persistent alterations in mental status, and abnormal findings on a neurologic examination, should prompt urgent neuroimaging and possible neurosurgical consultation.9
Numerous standardized diagnostic tools have been developed to aid in the recognition of concussions and to provide guidance regarding athletes’ return to play. These include the Standardized Assessment of Concussion (SAC), Postconcussion Symptom Scale and Graded Symptom Scale Checklist, Sport Concussion Assessment Tool 3 (SCAT3), Westmead Posttraumatic Amnesia Scale (WPTAS), and Immediate Postconcussion Assessment and Cognitive Testing (ImPACT), to name a few.10 A child SCAT3 has also been developed to assess concussion in patients aged 5 to 12 years. It is believed that children report concussion symptoms differently, so an assessment tool with an age-appropriate symptom checklist is required.4 These tools are useful in the sideline assessment of athletes who have potential concussion injuries as well as in the office setting, with serial monitoring used to determine the resolution of symptoms.11
The findings on conventional imaging are almost always normal because concussions are typically a functional and not a structural problem. However, if neuroimaging is being considered, brain computed tomography (CT) is typically the test of choice initially, especially for an acute injury. Magnetic resonance imaging should be considered for patients with persistent symptoms who are at risk for posttraumatic complications, such as headaches, vertigo, seizures, and postconcussion syndrome.12 Neuropsychological testing has been shown to be a useful adjunct, providing clinical value regarding cognitive function. However, testing is best performed and the results interpreted by a neuropsychologist, although there are currently no agreed-upon recommendations for the universal use of neuropsychological testing.4,11
Most patients with a concussive head injury can be managed safely in the outpatient setting. Observation with a responsible caregiver is recommended in the first 24 hours after an injury because of the slight risk for an intracranial complication.13 Admission to the hospital is typically recommended for patients with any of the following: (1) Glasgow Coma Scale score <15, (2) abnormal findings on CT scan, (3) seizures, and (4) abnormal bleeding parameters due to an underlying disorder or oral anticoagulation.14 A patient with an uncomplicated concussion is typically educated about the need for physical and cognitive rest for at least 24 hours. Certainly, this period can be longer if the patient remains symptomatic or the severity of the symptoms warrants continued rest. Cognitive rest is especially important in children and adolescents and should include abstaining from activities such as playing video games, watching television, working on a computer, using tablets and smart phones, listening to loud music, reading, and engaging in mental exercises requiring focus and concentration in the academic setting.15 This period should be followed by a gradual return to work, school, or physical activity, depending on the patient.4 Again, it is important to note that the majority of patients with concussion-related injuries typically recover spontaneously over several days.